Steer clear of astronomical, unexpected costs by deciding on a group budget beforehand. Reach out for guests' opinions and come to an agreeable consensus on how much you plan to spend. There are bound to be a few discrepancies, but go ahead and make plans according to the majority vote. It doesn't have to be all or nothing, either. For those who can't afford to join in on all the festivities, let them pick and choose which events they'll be able join.