OK, you've just gone up in my esteem a little for being a Linux user.
Yep, you can put together a "Hackintosh" running a hacked version of OS X if that's your thing. This kinda negates one of the advantages of the Mac platform in the first place though - the fact that, having standard hardware, you do away with the need for custom drivers and the hassle that can cause. If you crave hackability, and you enjoy tinkering with drivers and so on, then you could go this route and spend less. I've thought about it before, since I'd like something with the power of a Mac Pro, but can't really afford it.
The premium you pay for a Mac is for several things:
1) The OS and its associated bundled applications. The only legitimate and legal way to use OS X is on a Mac.
2) Cutting-edge industrial design and innovation.
3) Apple's excellent customer support.
If that's all worth it to you, get a Mac. If not, get a PC. Pretty simple really.
1) With a PC you usually get windows with plenty of apps. You have access to the widest library of software online ever created by mankind.
2) Not really. At the price you pay for it, you can have better design and innovation on a PC.
3) Single and only customer care, yes. As great as it may be, you can get free information about any kind of windows/PC problem by googling it. If you can't bother that, you can use one of the 1000s of cheap support hotlines anytime, or heck, call the neighbor. It doesn't get any better than that.
If that's all worth it to you, get a PC, If not, well, get a PC

