Quadro FX-3500

[KGH]

I'm looking for a card can do decent job on 3DS Max rendering.
How does this FX-3500 compare to GTX260 or GTX275?

I know they are diff class but what is the performance equivalent.
Trying to justify the price/performance here.

Specs

i7 920@3.8ghz
p6t
6GB ocz cas-8
640GB

thanks