The original concept of Coffee, Coins, & Sigs was to be an event costing us nothing to host. We were working with a local coffee shop to host at most a couple dozen cachers and they'd sell some drinks. Unfortunately the "will attend" logs for that first event rapidly grew too large for the local coffee shops and we had to move at the last minute to a rented facility and supply the refreshments ourselves. We spent something like $500 on that first event and did receive something in the neighborhood of $100 in donations. Since then we've been able to plan for the bigger crowds and get in about the $200 or lower mark. Usually we've been able to find a partner in a park service wiling to donate the room meaning we only need to supply the refreshments (this last time only cost about $140). We even once found a facility with a coffee bar to rent the room freeing us from the management of the refreshments. Unfortunately there can be a cost to hosting successful event concepts so it's worth thinking about when you're planning that next great event idea.