When I did that I was lucky enough to find a decent Seneca I for $100/hr dry... the prices didn't really go up but since you paid for fuel yourself you didn't get hit with crazy fuel surcharges that you scratch your head at, and could plan xc's around the cheapest fuel spots and cruise at 17gph. The Multi instruction was like $35/hr so with fuel/instr. it came to be about $180/hr total. Now it's probably around $215/hr. with instr.
This place also has an 172sp for $65/hr dry. For me the "dry" was the way to go.