I'm trying to decide between these two setups.  I can either go with 4 750ti.  I have 1 now that gets about 300kh/s and i think I could get it up a bit with a powered version.  

I don't have a 270 but hear they get around 400kh/s

270s are $250, and 750ti are $150.  Plus I would need to spend a little more on a PSU for the 270 setup.

obviously the 270 setup is more expandable without having to build another rig and with the right PSU

Whatcha think?

Edit: i forgot to mention these are just about the best setups i could afford right now