Hey dude, Fenken picked out a real good one for you. I just went up to that 700 mark you told me. This set up is 695$ (665$ option available with other CPU). Mind you the amazon.com shipping is free, but the rest of the components are from newegg, if you bunch em up it might cost you about 10 to 15$. Also what I suggest lots of big computer stores these days, especially ones that focus on custom computers and computer hardware exclusively, will do match the price type thing (and maybe even beat it). So check around locally for either what Fenken suggested or what I am suggesting.
Just a little info on the hardware here, the case is standard, nothing too complicated, it has one big fan good sturdy design. PSU is 730 watt and can handle crossfire (when you put two video cards together), motherboard has enough for two vid cards (if you ever wanna upgrade), the CPU is one of AMD's best 8 core 3.6ghz. I have that RAM and it gets me a 8.9 windows index. SSD read and write speeds are 520 550, compared to a HDD which is around 80 to 100 (and it's a MASSIVE boost in all around performance, my macbookpro has one of these, and boots in about 12 seconds, prolly 15 with windows) but it's only 120gb, so we'd have to take the one out of your laptop and install it here for storing stuff, but I could guide you through that, so the SSD would be where you put Windows, STEAM, and all your games and programs you wanna run FAST. And finally in the price you get a video card, the 6850 which is by far the best GPU for the buck on the market, you can play anygame, but maybe not always on best settings.
So this'll put you back 695$ or 665$ if you get the slightly less better CPU (also 8 core but 3.1 ghz), BUT compare prices @ tigerdirect.com , newegg.com, amazon.com and ncix.com. Cause you'll also need a monitor and keyboard.
(also if you do decide to go with fenken's choice of components, basically what you'll be losing is processing power, refer here cpubenchmark.net, graphics power videocardbenchmark.net , and start up time. But if you do decide to go with Fenken's choice (which for the price is also the best you can get) switch the HDD with the SSD below)
Case: 49.99
http://www.newegg.com/Product/Product.as...6811133094
PSU: 59.99
http://www.newegg.com/Product/Product.as...6817152036
Motherboard: 84.99
http://www.newegg.com/Product/Product.as...6813157280
CPU: 199.99
http://www.newegg.com/Product/Product.as...=fx%208150
or
169.99
http://www.newegg.com/Product/Product.as...6819103961
RAM: 59.99
http://www.newegg.com/Product/Product.as...6820231468
SSD: 97.99
http://www.newegg.com/Product/Product.as...6820226236
Video Card: 139.99
http://www.amazon.com/GIGABYTE-Radeon-Di...words=6850
PS. If you ever decide to go laptop, DO NOT get an i3 or i5, too much lag, go i7 without a doubt. but if you're gonna game, just keep the laptop you have for storing stuff and on the go, and keep your desktop gaming only.