You aren't going to get bleeding edge components for under €500.

Most people's idea of top notch support is a friend or relative who works in IT. I know that none of my friends of family would ring a support line or go back to the shop, without first seeking my advice. Apple's support, here, is either a send-away service to a third party European hardware repair service or taking it back to MediaMarkt or Saturn, like any other manufacturers hardware - and it costs more here than in the UK!
Again, most people wouldn't know a work flow from a Crossflow.
Great build quality? No offence, but the build quality on the 4 or 5 PCs I've replaced in the last year was great - they had all made it to at least 9 years old with all original components and still in good working order, nothing rattled or squeaked. What more do you want?

Yes, they are great looking, but that is a matter of taste. A couple of the people who replaced have bought all-black, shiny piano black finish machines with matching monitors. Beauty is in the eye of the beholder.
Resale value? If you are planning on buying a PC that will be replaced every 8 years or so, you don't really care about resale value.
I do have an iMac, what made me buy?
- The OS, but I know it had a different OS and wanted to try it - Windows XP had driven me away from Microsoft, and I'd been using Linux as my main desktop OS for 4 years, so I was willing to give it a try.
- The price was competitive - it cost about 20% more than an "average" PC on the high street, with a 24" monitor.
- It used laptop components, so used less power than a normal PC.
Resale value, looks and build quality didn't come into it. As I have never re-sold a PC, the looks didn't match any of the other machines I have and I assumed, for that price, if my cheaper machines last at least 8 years in an operational condition (I have some with are still running after more than 15 years), then the iMac should be at least as reliable.
Today?
- Having used OS X, I know it is very nice, but it isn't worth a price premium to me - but all of the tools I use are available on Windows, Linux and OS X and work pretty much the same on all platforms.
- The prices are no longer competitive. Instead of being within 20% of an "average" PC (with monitor), they cost nearly 200%! They are no longer good value for money.
- Other manufacturers are catching on to this are working on lower power consumption in general
To get back on argument, the average user won't spend 2K on a PC, when they can buy a functional machine for a quarter of that - and I don't mean Apple kit here, I mean gaming machines, workstations etc. as well.
Looks are important for some users, but look at what most of the manufacturers are producing these days, in the low end to mid range market. They may not be up to Apple standards, but they do get the average person to stop and go "oooh, shiny!"