Your best bet is to stay clear of DX10 for now - because first generation cards are always pretty slow compared to things that will come out in a year or two (when there are enough DX10 titles to actually make you WANT to buy a DX10 card.) I bought a 7600GT a while back for $105, after rebate, and that was almost 6 months ago, so I'm sure you can find it for the same price or cheaper now, and the card works GREAT.
I play Half-Life 2, Warcraft 3, World of Warcraft, and a few other games all at 1920x1200 on my Dell 24" monitor, and they run above 30fps for the most part. You don't need 2000fps and a GeForce 9,000,000GTXXXXX to be happy... the direct x 9 engine has pretty much been maxed out, and the 7600gt is a GREAT card to handle the types of games you might throw at it. I recommend buying this card, and then maybe waiting like a year or so, at least until crysis comes out, so you can have more options at the table.