empire,
With just the quick information you gave us, I would say around $1.50-$2.00 a sf, this all depends on if it’s on concrete, if its in a wide open space or not, and how clean they want the floor when your are done.
There is a skid steer attachment that can do about 3000 sf per hour I have used it a couple of times and average about 2250 – 2500 per hour. Here is the link to that:
Schibeci Power Profiler
Let us know if you need anything else
James
(P.S: Sorry for the delay I have been in meetings almost all day)