18Greens - hear what you say. I know of a group in a C120 with about 18 members, and it does about 90 hours a year - as the Americans say - go figure.
I'm in the Group market too (ooh er), and am amazed at the seemingly dodgy state of affairs some groups seem to operate in.
Example 1. Someone was trying to syndicate his C172. Reasonable nick. Standard monthly/hourly rates. Found the catch after some probing - engine hours up to 1600 and no engine fund. tried to pass it off as if it was not a problem.
Example 2. DR400 group. Lovely a/c. Very hefty buy-in figure, standard monthly/hourly rates. Again, no engine fund and no emergencies fund, so any non maintenance repairs come out of the pocket. I prefer to plan for things more carefully than that.
I'm not casting aspersions on the 2 examples above. They probably run well, but there seems to be ample potential for it to get very ugly...