Walk into any optical shop for a new pair of prescription glasses and you’ll likely walk out $300 to $500 lighter. Order the same prescription online and you might spend $30. That gap isn’t a fluke or a quality compromise – it’s the basic math of what changes when a product doesn’t need a showroom, a commissioned sales team, or $40-a-square-foot retail space to reach you.
Not every product works this way. Some categories are genuinely a wash between in-store and online prices, and a handful are actually cheaper in person. But there’s a specific set of products where the savings when you buy products online cheaper aren’t marginal – they’re structural, consistent, and often dramatic. These are the categories where the retail channel itself is inflating the price, not the product’s actual value.
According to a 2025 report from Capital One Shopping, approximately 2.77 billion people worldwide made purchases online as of 2025, with online shopping revenue hitting about $6.42 trillion globally. But raw volume doesn’t tell you where the deals actually are. That requires looking at which specific categories carry the heaviest retail overhead burden – and therefore have the most to shed when they move online.
Prescription Eyeglasses
Prescription eyewear has become one of the biggest success stories of online shopping. Traditional optical stores often charge hundreds of dollars for frames and lenses, while online retailers disrupted the industry with significantly lower prices. Zenni Optical starts frames at just $6.95 – a figure that sounds impossible if you’ve ever paid $180 for frames at a mall optometrist’s kiosk. Many shoppers report buying multiple pairs online for less than the cost of a single pair at an optical shop.
It’s often cheaper to buy prescription eyeglasses online rather than in person because companies operating online-only stores don’t pay for retail storefronts, overhead, or floor staff. Virtual try-on technology and home measurement tools have also made consumers more comfortable purchasing glasses without visiting a store, reducing one of the few remaining reasons to go in person.
One thing that makes this category especially actionable is the FTC’s Eyeglass Rule: under this federal regulation, your eye doctor must provide you with your prescription at no extra charge, meaning you can take that prescription and compare prices at any retailer you want, including online. If you wear glasses every day and haven’t tried buying them online yet, you are paying a significant premium for the experience of standing in front of a mirror in a retail store.
Mattresses
Few product categories have been as thoroughly reshaped by e-commerce as the mattress industry. DTC (direct-to-consumer) brands and online retailers operate at margins that traditional furniture stores can’t match because the cost structure is fundamentally different – no per-square-foot mall rent, no commissioned floor staff.
The numbers back this up consistently. According to the J.D. Power 2025 U.S. Mattress Satisfaction Study, consumers who bought their mattresses online spent an average of $984, which is $258 less than those who bought in-store, and online shoppers scored 9 points higher on overall satisfaction. The study also highlights a five-year trend in which retail shoppers consistently rate the value received for price paid lower than online shoppers do – meaning the gap isn’t just financial; in-store buyers feel worse about the deal afterward, too.
By 2025, online mattress sales captured more than half the total US market. The shift is real, and the consumer satisfaction data suggests people aren’t regretting it. The main caveat worth knowing: some online mattresses are genuinely well-priced, while others are marked up just like store models, with the savings going into Facebook ads and influencer payouts instead of showroom rent. Trial periods of 100 nights or more – which have become standard online – give you a way to test without committing.
Electronics and Computer Components
Electronics – including TVs, cameras, tablets, phones, and more – have long been cheaper, on average, online than in-store. The driver is competitive pressure. Multiple online retailers selling identical SKUs (stock-keeping units, the specific model numbers) forces prices down in a way that a single physical store simply can’t match.
Technology components are particularly competitive online, which often drives prices lower than those found at electronics retailers. Memory upgrades, SSDs, and other computer components frequently go on sale online, and shoppers can use price-tracking tools to monitor discounts. For anyone building or upgrading a computer, waiting for an online deal can sometimes save well over $100 on a single purchase.
Phone accessories are a stark example of the in-store premium at work. A quick trip to a mall kiosk can result in surprisingly expensive phone accessories. Online marketplaces offer thousands of competing options, often at a fraction of the price found in stores. In many cases, generic versions provide similar protection and durability as branded alternatives. A phone case that retails for $45 at an airport shop is available for $8 online with equivalent protection. That’s not a deal – that’s just what it costs when there’s no captive audience markup.
Books
Books remain one of the most consistently discounted product categories online. Major retailers frequently offer lower prices on new releases, while used-book marketplaces create additional opportunities for savings. E-books can lower costs even further. Many readers admit to browsing physical bookstores for inspiration before purchasing the same titles online at a reduced price.
This is one area where the behavior gap between what people do and what saves them money is particularly wide. Independent bookstores carry real cultural value – the browsing experience, the staff recommendations, the community – but if the only metric is price, online is almost always lower. For heavy readers going through two or three books a month, switching to online purchasing (or using digital library apps like Libby for free) adds up to real annual savings.
Vitamins and Supplements
Vitamins and supplements are a category where the in-store premium is driven almost entirely by the cost of store shelf space. Pharmacies and big-box stores stock a limited range at full margin. Online, the selection is vastly wider, the competition is fiercer, and subscription models – where retailers offer 5 to 15 percent off recurring orders – don’t exist at your local CVS.
You might not think of buying your supplements online, but the savings are real. Online retailers often sell items in bulk or offer discounts you won’t find at a drugstore counter, and subscribe-and-save options compound those savings for items you order repeatedly. A 90-count bottle of fish oil or magnesium glycinate bought through a subscribe-and-save program online routinely costs 20 to 40 percent less than the equivalent at a pharmacy. The product inside the bottle is identical. What you pay extra for in-store is the convenience of impulse purchasing and the retailer’s margin on that impulse.
Auto Parts
Whether replacing brakes, filters, or sensors, vehicle owners often find far more competitive pricing online than at local auto parts stores. Online retailers provide access to multiple manufacturers and both OEM (original equipment manufacturer) and aftermarket options. For DIY mechanics, comparing products and prices across numerous sellers can translate into significant savings on vehicle maintenance.
The in-store auto parts markup is substantial and partly driven by urgency – people tend to walk into AutoZone or O’Reilly’s when something has gone wrong and they need a part today. When you can plan ahead, ordering online first is consistently cheaper. A set of brake pads that runs $65 at a local chain might be $38 for the same brand online. Air filters, wiper blades, and oil filters show similar gaps. The exception is if you genuinely need the part immediately, where the in-store premium is essentially a convenience fee for same-day availability.
Household Cleaning Products and Personal Care
Buying household cleaning products online is one of the easier ways to cut costs on everyday spending. Products like dish soap, laundry detergent, and cleaning sprays are often cheaper when bought online, especially in bulk. Concentrated versions of products last longer and lower your per-load or per-use cost compared to standard retail sizes.
The savings here are consistent enough to change how you approach these purchases – not as one-off trips to the store when you run out, but as periodic bulk buys online. Laundry detergent, dishwasher pods, paper towels, shampoo, and toothpaste are all products where online bulk pricing undercuts the grocery or pharmacy aisle by a meaningful margin, with the added benefit of not having to carry a 100-ounce container of laundry detergent through a parking lot.
Pet Food and Pet Supplies
Pet food is a category with a nuance worth understanding. For many types of products, online retailers offer the lowest prices – but that’s not universally true for pet food. At warehouse clubs like Sam’s Club, BJ’s, and Walmart, in-store prices can compete or even win. According to an NBC News report citing consumer research by Checkbook.org, Chewy.com was the least expensive online option for pet food, with prices about 11 percent lower than the all-store average – but Sam’s Club came in 22 percent lower than the all-store average, meaning warehouse clubs still beat online on pure price. The practical trade-off is convenience: someone else handles the 50-pound bag.
The real advantage online for pet owners isn’t just the base price – it’s the auto-ship programs. Many online pet retailers have auto-ship options, which not only make life easier by delivering pet food on a schedule but also come with recurring discounts. For pet owners who buy specific prescription diets, specialty supplements, or niche brands, the online selection advantage alone justifies the shift, since stores will never carry the full range of what’s available.
Printer Ink and Office Supplies
Printer ink has long been notorious for its high markup, particularly when shoppers need cartridges immediately and buy them from a local retailer. The emergency purchase situation – running out of ink 20 minutes before you need to print something – is exactly how retail stores capture maximum margin on this category. Buying compatible or remanufactured cartridges online, or even OEM cartridges through bulk subscription programs, can cut costs by 50 to 70 percent compared to grabbing a brand-name cartridge at an office supply chain.
Office furniture follows a similar pattern. Online retailers like Wayfair and Amazon carry far larger inventories of office chairs, desks, and shelving than any physical store can display, with competitive pricing that eliminates the showroom overhead of a furniture retailer. For anyone who’s priced a decent ergonomic office chair at a store versus online, the difference is often $100 to $200 on comparable models.
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Why the Price Gap Is So Predictable
Online retailers don’t pay rent for storefronts, they employ fewer people, and they can pass those savings directly to you. Brick-and-mortar stores have to cover costs like rent, utilities, and wages – meaning they mark up prices just to stay profitable. When a product can be photographed accurately, described precisely, and shipped in standard packaging, there’s no economic reason for the consumer to absorb the cost of a physical retail location as well.
The categories where online isn’t cheaper tend to share a different set of characteristics: perishable items that need same-day freshness, products that genuinely require in-person fitting or testing (custom-fitted clothing, hearing aids, certain medical devices), and purchases where urgency overrides price. Everything else invites a practical question: am I paying a location tax on this?
American consumers have become increasingly cautious about spending. According to Capital One Shopping’s consumer behavior data, 72 percent of consumers now express concern about the increasing costs of everyday purchases. Knowing which purchases carry avoidable markups is one of the more practical ways to act on that instinct without changing what you buy – only where you buy it.
The shift doesn’t require becoming a bargain hunter or spending hours comparing prices. It requires identifying which of your regular purchases fall into these categories and routing them online by default. Prescription glasses you’d replace anyway. Vitamins you take every day. Laundry detergent you’ll always need. These are not exciting purchases – but they’re exactly where consistent, structural savings accumulate without any sacrifice in quality.
AI Disclaimer: This article was created with the assistance of AI tools and reviewed by a human editor.