Is 1 Geforce GTX 275 better than my 8800GT 512MB SLI setup?

I have a 8800 sts 512mb to. And I was planning on getting 2 more considering they are $100 now. So my question is, Running 3 of these, would it be better than 1 GTX 285 or 295? Or should I just trash these video cards. Im guessing running 3 at once will be a pretty brutal set up? Please let me know.
 
2 8800GT 512 in SLI are still solid cards and perform well i don't think u have a bad experience with them right ?

and your guess is right,GTX 275 and 2 8800GT 512 in SLI perform closely to each other,keep your cards IMO it isn't worth it to upgrade from them to 1 GTX 275.