^ Seconded.

As for your potential new 'puter, 700 USD should be plenty for a computer that can run a fair share of games.
I live in New Zealand, and our dollar is weak against the US dollar; even so, I managed to get this laptop I'm using right now a year ago, for a grand total of 800 NZ dollars (600$ after cashback, lol), and after scoring another gb of ram for $35, it can still hold it's own against newer (read: flash) laptops. The only penalty I've paid is light burns to my left thigh from the air vents after a good session of Half-life Deathmatch.
Your mighty US greenback is worth roughly double our dollar, so you should be able to get a very nice desktop computer. (Unless americans are tight bastards)


In short, shop around. You should have no trouble buying a premade computer that can play games equal to and perhaps even surpassing goldsrc games. (i.e. Half-Life 2, Counter-Strike Source, that stuff)

If you can, make sure the operating system is Windows 7, not Vista. Vista is a cockblocker when it comes to resources, and if you want to get max game from minimum budget, you'll need those resources.