I think it would be a good idea to let members be able to donate to the group coffers. This would let groups become richer, and perhaps hold more events and more prizes and such.

It could let the group be more well known and attract more members also, an investment of sorts. Some groups don't have many members so their coffers are not so big, though the members within it may be very active and such ... I think it would just be nice.

Also a generous way to make the purse lighter. Perhaps it could be to any group though instead of just the one(s) the person is in.