I'd say $25 or so an hr is quite fair, and if its on the Reynoldsburg side of 270 i think you might even get some people from the eastside, i know i'd drive up from newark. hell hurry up and do it, i've been putting off doing my headers and exhaust untill i find a lift lol.
I would say it would a good idea to have a few guys there at all times who know cars inside and out, you could even put on demo's and classes for people wanting to learn how to do something to help pay the bills.
Good luck with it, i see no reason why if everything is ran properly this couldnt be a sucessful venture.