Wait, is tax rate for fellowship different??? I think the city tax withholding rate is already 2.5%... Anyway, what I am saying is, if you need to pay taxes for fellowship, you should expect the rate to be much more than 2.5% in Columbus.
The rental prices depend on a lot of things. Usually, it ranges from $300 to $700+ for a single room close to campus. If you want to find a one bedroom or studio, be prepared for at least $550 a month; if you want to have roommate(s) to share the rent, usually you need $400 to $600 for a decent to nice place. I'd say Columbus is a nice place to live, and is still less expensive than most major cities, but the winter here is toooo cold for me...
Congrats to your fellowship! Have you decided to come to OSU?