It varies, of course. But living in the city is going to be way more spendy than you're used to. I'm in Westminster (about 10 minutes outside Denver) and I paid $800 plus utilities for a smallish 2 bedroom apartment. Then I moved to a 3-bedroom house in the same area and split with 2 other guys. The total is $1400 plus utilities.

I actually only pay a $500 flat rate and the lease isn't in my name, but that's probably an unusual situation.