As mentioned above, for what you want to do, the relative hourly costs are not that great a comparative tool. While the Cessna may be half the hourly rate of the other two you will spend approximately twice the time climbing to height/regaining height after spinning, or any given figure two-up. Something like a Pitts or Extra is more than worth the higher price and in your situation I wouldn't even bother looking at a Cessna. Also since, as already mentioned, an aerobatic sortie will be more like 40 mins than 1 hour - assuming you don't have to faff around transiting - you won't be spending that much more in real terms.