Exactly Sams88. I did that once with a dual P2. Tyan Tiger 133 board. Imported it myself. I thought I'd need the power. 2 years later the newer cpu generation tore my hyper-dual-1gb-ram box apart as if it was a cheap throw out from walmart. 
I'll admit that I drool over alienware, sony and samsung stuff. Next year maybe I'll try a newer Vaio or Samsung slim thingy. I'd never buy a apple notebook. Silly prices for a friggin' intel machine.
alienware is not worth the money. comparing two laptops you get the same specs for an extra thousand dollars, and the alienware looks retarded.
The Alienware laptops are a bit overpriced because of branding and because you are asking for frigging Desktop performance on a laptop, so of course you are going to get milked

But the Alienware Desktop offerings are also a bit expensive, but it is has consistency in hardware and drivers, unless you know REALLY what the heck you are doing you are better off buying a properly designed and tested Alienware tower than doing a custom job. My PSU for my eGPU broke down because "surprise" the cheapo ebay stuff couldn't cope with the voltage requirements and a proper volted PSU is about 200£ ... and my motherboard is getting
"NO RAM" error each time I connect the frankeinsten graphic card to it. I sold every single component of it, I can't take it anymore.
I will probably have to burn the receipt so my parents don't kill me to spending that much money (of my own money) on a
single computer, but something like this is more suitable :
http://www.dell.com/uk/p/alienware-aurora-r4/pdBut you get a consitent quality, and a better updatability out of it.