Best Buy,
The store where the sales people know less than you think, and see how much of a rube they think you are by preying on your fears.
If I didn't have ethics, I could make over 100K a year working in sales for them. Yes, I know how much their salespeople make on average.
Sometimes having to work in the BOFH position gives you the ability to execute

.
The truth is that Best Buy makes their money on software and services. They make next to nothing on PCs. No store does. The only companies that do are Dell and Apple. PCs are big money-losers to sell you game software, anti-virus software, anti-spyware software, anti-spam software, and other accessories which you may or may not need.
Dell does because they have one of the best supply chains in the industry, and the Wal-Mart like tactic of screwing many of their vendors.
Apple charges a lot more than the other PC vendors, however they do deliver a quality product (most of the time) that has a very solid OS and application bundle behind it. They are the BMW of the computer world, and charge accordingly.
HP/Compaq, on the other hand, makes money hand over fist on Proliant servers and printer ink. They make more money bundling a printer with a PC than the PC itself due to the fact that buying the ink makes them the profit. The Proliant servers are everywhere and are an industry standard. Those servers are probably the reason why HP bought Compaq. Their x86 server line before the Proliants was not good. HP makes more money on Printer Ink than Proliants. Does that tell you anything?
Gateway/eMachines makes money apparently from "kickbacks" from the vendors for installing trial versions of their software, namely Symantec (who is rolling in dough from Microsoft's perceived inability to produce a decent OS, and who purchased Veritas with money made from the fact that XP wasn't built well).
Not to sound like a conspiracy theorist here, but the reason you don't see Mac OS X, Linux, or other OSes pushed is because you can't sell a ton of corollary services and software around the product to the consumer. What good is a product that you sell at a 2% profit margin (max) which doesn't need several hundred dollars of additional software with yearly subscription fees that sell at a 50% margin or better? Why be in business selling PCs if you can't make a decent profit margin? Not enough people buy game software.
You can sell all of those services (read: very expensive app servers, customized POS systems, and software like Oracle) to corporate customers, which is why IBM Global Services makes a lot of money on alternate OSes like Linux.
You're just seeing the American business machine in action. Nothing personal, it's just that PCs take up a lot more space than a DVD player or iPod in the warehouse, and therefore it costs a lot more to sell it. Someone's got to make up the margin cost.
Mitch