If i where you I would try and get the GPU/CPU second hand, theres alot of cash to be saved by it. And people throw away hardware, when new comes out - You can get a good cpu like a E8400 (dual core) or Q9550 (quad core - Though its not really getting used by any game yet) for little to no money. Im talking in the area of 70 to 100 dollar.
Those would still hold out quite some time, one doesnt have to change major hardware unless something drastical happens (Im running a close to 5year old machine, with no issues on High/Multiple graphic mods)
A good GPU like the 260/2 is a tad hard to get ones hands on here in Denmark, since its a really good card, that still push out pixels great. (I Go the Nvidia way, for the ease of Drivers) It would perhaps be in the 50 to 90 dollar area and below by now.
With those two, all you would need is a solid Motherboard (I would recomend a p5e, cheap and stable) and a batch of RAM, wich is genneraly trown after you for less than 50 dollar for 8gb of a good manufacture.
Thats like 250 to 300 Dollar for a pretty good start - the money would at the moment be spent on the OS (250 Dollar for a win7 in Denmark) and a harddrive, theres been some issues in given contries (Like eathquakes) so the prices have rissen quite a bit.
I appologize if this info is of no use to you. I'm just trying to open a door, to perhaps saving some cash - Since with the last few years of Gaming on a pc, havent really evolved any bit (New games like RAGE and such really doesnt take a huge machine to play, I wont comment on why though

EDIT; Sorry about the poor spelling

But if youre settled on using 1500 dollar ? All I can recomend is, get a good PSU mate. (one capable of delivering the amps needed, not talking about watt) With that budget we're talking a whole different ballgame. (wish I had that money to burn atm - what a machine one could build
