FO3 Platform conversion

Sup /games/,
I read from time to time but I figure I'll post here for the first time since i want a serious answer.

I have the 360 version of Fallout 3, but I want to exchange it for the PC version so i can start modding for it, but my computer isn't up to speed, and since i kinda want to get more into the PC gaming world, I think I should get a whole new gaming rig.

Where should i be looking for a new comp? Microcenter? some place online? Are there any vidya related features i should be looking for? what is a reasonable price? is this a /g/ question?

bump?

build one yourself

amd phenom II x4 945
ati 4890hd
4GB DDR2 RAM

good price/performance

approximately how much does that cost?
where should i get it?

>>4
it costs 650€ including case/psu in my country
if you're in america it should be cheaper I think

>>3
i estimated about 650$ for just these components via google. assuming i can salvage a monitor, keyboard and mouse, what else do i need and how much would it run me?

>>6
650$ for just the three components I listed? that sounds expensive, my prices also include 19% vat. but my experience with american prices is kinda outdated (dollar was still at parity with euro back then) try looking at newegg.com or something
I counted 650€ for everything inside the case except hard drive

here's the rest:
am3 ddr2 motherboard 60-70€ (i always get one with sound and lan built in)
case+psu 100€ (you can save some on the case but always get a good psu if you should buy these seperately, although it's usually a better deal to buy a (example) antec case which includes 500W antec psu)
750GB hard drive 60-70€, maybe 1TB is a better deal, you should calculate yourself how much it costs per GB, also, I heard bad things about Samsung HD's... almost as bad as IBM's click-of-death series

>>7
I got 320$ just by converting your prices, but i still have no idea what i am supposed to be looking for. im guessing 970$ (690€) isnt bad for a comp? again, i have no idea. is there anything i can cut since its going to be strictly for gaming/ modding? is their anything obvious im missing since i have no clue what im doing? like an OS?

thanks for helping me out mate