Maybe it's different in Europe. I can buy a good Dell computer for $1100, the equivalent Mac is about $1500.
I don't believe you. Prove it: show me the numbers.
I just tried recreating the base Mac Pro configuration on Dell's pages, and ended up well over 3000 €. The prices here are more or less the same as in the US, after accounting for differences in VAT.
Then I tried recreating an iMac configuration on Dell, and ended up at about 1,400 €. The equivalent iMac was about 1,500 €.
If I went and built a computer myself (something I believe you just can't do for Macs) it would have been about $800. 2 years from now I can open the computer, pull the video card and throw it away, and for $120 I can upgrade the video performance 50%. For a Mac you have to buy a new one, try to sell the old one on ebay or craigslist see if some fool would buy an already old computer that can't be upgraded.
But that's it right there -- there are plenty of those "fools" around, when it comes to Macs: as txa said, they retain their value much better, making upgrading by swapping a perfectly viable alternative economically. Of course, if you *want* to tinker with hardware (I do, for the record), that's not an option -- but that's a matter of personal preference, not money.
IOW, if you don't *like* Macs, think Mac-heads are snotty stupid non-technical peons or whatever, that's one thing -- but your stated reasons for thinking Macs don't make the grade just aren't true.
A Mac is not the 'BMW of computers' anymore. They use same generic parts everybody else uses. The only real difference is the OS, and they know that, that's why they refuse to let anybody put their OS in other hardware, it would kill their golden egg hen.
There are hardware differences too, but on the whole you're right: they do use off-the-shelf parts. However, they use considerably better off-the-shelf parts than Dell, HP, or the other box movers. Just look inside one, you'll see.