To add some more figures:
Our group (pfa two-seater) figures are: Share- £2500 (there are six in the group), monthly- £28 (covers insurance, hangarage, radio licence, paperwork etc.) Hourly- £9 per hour dry charged on airbourne time only. Each member buys their own Avgas and leaves the tank brim full after flying. Fuel burn is 18 litres per hour so you can work out the economics. The group is sufficiently well run for us to have been able to have the engine zero-timed last year !
With a well-run group your flying time is limited by the time you have available, not the cost.