If your budget allows, get the GF3, you won't be sorry you did, besides you could sell it later and get a good buck if say the Ultra or better comes out.
If you buy a cheaper card now your chances of getting a return on it will be minimal.
I always get the latest and sell my old one so my upgrade is always cheap.
No one wants outdated technology especially after 6 months, but if you have the best now, you get a higher return for your money later.
I used to go the other route and always ended up paying through the nose, now I upgrade regularly, sell my old, which is new to alot of people, theyr'e happy, I'm happy and the upgrade path is cheap.
Don't make the same mistake I did for years.
Again, only if your budget allows.
That's how I got started building computers for people, buying selling and upgrading.