Out of interest, why is typically the rate for hiring a Pitts S2 so much more than an equivalent value aircraft? Is it just that you'll be using a lot of fuel in that hour? Or insurance maybe?
Maintainance is more, Engine life is shorter, insurance is more, hangarage is needed and useage is also probably lower.
Alan C makes a good point in his book. It might be cheaper per hour for a Cessna aerobat but you will fly for twice as long and all the extra time will be spent climbing for height.