okay i did some more research and these are the areas of cards id be most interested in...
geforce GT 520 1gig for my low end price (anyone want to chime in on difference between these and the GT 4XX cards as they seem to be pretty similar in price). is DDR3 memory something i should totally avoid or not a big deal
and a geforce GTX 550 (ti?) 1 gig for my high end card - is it unrealistic to hope someone would let one of these go for under $100?
Considering you can get a new 550 ti for $125 I don't think under $100 used is unreasonable.