I'd hold off and grab a GeForce 6800NU for $299 when they come out if you can wait until around June or so. Of course, I'm expecting some MAJOR price drops once the 6800s are readily available. I figure the 5950's will turn into midrange parts briefly before they disappear, so you might be able to snag one for around $200-$250, and this downward price move will probably force the 5900NU card down below $150 level and might make the 5700 a sub-$100 part. The big question is what will happen to parts like the 5500, which are going to wind up being so cheap that the 5200 cards will have to be sold FAR to get them out the door (which I wouldn't put past OfficeMax).
There are way too many versions of the FX series cards floating around in the retail channels now and they already are competing against each other, like the 5900NU eating into the sales of the 5700 because they are so close together in price, that it is going to take a fire sale to get a lot of inventory cleared out. It is a heck of a lot worse than when I picked up my 4200 Ti for a song last year, since back then there only really was the 4600 Ti and 4200 Ti to worry about since the 4400 had already faded from sight by the time the FX cards were introduced. Take into account the flood of 5900 and 9800-series cards that will be hitting the FS/FT forum shortly and eating into the sales of the retail cards, and I think a lot of retailers will be desperate to get the FX cards off of the shelves.
And this is not even taking into consideration what ATi plans to do when the X800 cards hit the shelves.
I'd hold off and suffer with your GF3 Ti 200 for a little longer until all the new pricing gets sorted out. Right now it looks like anyone buying a new card right now is going to be kicking themselves in a month or so for not waiting.