Are SLI GTX 260 any good?

how much you can get for the second GTX260? nvidia has been EOLed the card for quite sometime so it is lucky if you can get brand new one. if you don't have any problem to pick used card then it should be cheap performance upgrade for you. performance wise GTX260 in SLI should perform around GTX295 performance (which is equal to single GTX480 or GTX570). GTX460 1GB (non SE) is about the same as GTX285 in terms of performance but when heavily overclocked it can match stock GTX470 performance.

Don't buy another gtx 260. Move on to directx11. AMD 7xxx series out 2011 Q4 and you can expect nvidia to retaliate with keplar in 2012. Squeeze out whatever life you have out of your current gtx 260 and then set it aside for a second build if you want.

^ I second that, I also was thinking on getting another 460 for sli, but I'll wait for next generation. Upgrading from a 260 to a next gen GPU would be a giant leap.

I only found a 260GTX 896Mb, NOT a 216 model on Newegg and it was $100USD.
Save your money like wintermint says keep looking. What is your budget, monitor, rest of your set-up?