Budget graphics card for a couple months

What I'm doing is building a gaming rig, and for now, I need something that can play pretty much most games out there, even on 800 x 600 lowest graphics. I just need 40+ fps. The more I save on the GPU now, the better the system specs on everything else can/will be. My options are:
$10 - Zotac GeForce 8400GS 512MB
$20 - Gigabyte Radeon HD 5450 512MB
$25 - Galaxy GeForce 9500GT 512MB
$30 - Gigabyte Radeon HD 6450 512MB
$30 - Zotac GeForce GT 520 1024MB
$30 - Zotac GeForce GT 430 1024MB
$40 - Sparkle GeForce GT 210 1024MB
$44 - Zotac GeForce GT 440 1024MB
$45 - XFX Radoeon HD 4670 1024MB
$50 - Zotac GeForce 9800GT 512MB
$50 - Gigabyte Radeon HD 5670 1024MB
$60 - Sapphire Radeon HD 6570 1024MB

And for 13 cents I can get a NGTX 999GSTi+ Superoverubermegaclocked 14TB of GDDR8 SDRAM, but I don't think it's a good deal...

Which one has the best performance/value ratio? I'm only looking to play Fallout 3/NV, Oblivion, Valve games and stuff for now, then I plan to get a GTX 580Ti or something at Christmas.

P.S. My current specs are...
AMD Athlon X4 645 3.20GHz
NVIDIA GeForce 6150SE
Antec Earthwatts 650W
512GB Solid State
4GB DDR3 1333MHz SDRAM