Have 8800 320 GTS... anything worth $250 upgrade??

Hmm, you're probably starting to approach the resolution limit for that amount of VRAM.

The only thing better in your price range is probably the GTS 512 (You may be able to find it for like $260-280 w/ a MIR) or the 8800GT 512MB.
I don't know if the performance increase would be worth the price though.

I know how you feel, I have the 320 8800 and an upgrade would be nice, its not quite necessary yet, look into maybe some more ram or a better proc. Then again, I don't know what your specs are...

8800GTS 512 is at $289 on Newegg  

Yeah, at the time... the $250 part was next-generation & a no brainer (over the Nvidia 7000s and ATI 1900s). It truly took performance to a whole new level for the price. I guess my question is, is there a $250 part out or (coming out) that will be that similar "next level" price vs. performance.

I'm not looking for some marginal improvements. Maybe I have to wait 2 years (instead of 1) to get such an improvement???

I call it generation skipping. Basically I had a 6800, skipped the 7series and then jumped to an 8800. Next upgrade for me would be whatever comes after the 9series, unless the 9's totally rock and are pretty cheap too.

It just makes it more worth my time and money to only upgrade when there will be a big improvement, not just 5-10FSP. Anything less than a 20% improvement really isn't worth it to me unless I'm really down on my FPS. Even then it'd have to be an awesome new game to convince me to upgrade.

I don't know what your system specs are but a shiny new e8400 might be in order. It might not help your games all that much but it will help everything else as well as your games so it might be more worth it overall.

^^Agreed.

The 8800GTS 320MB still has a good year of life left in it IMO. By this time next year the 9800GTX will probably cost $400 or $450, like the 8800GTX now. Start saving...