Expenses wise, the worst part is always starting up. Once you're up & running it's not so bad & as Lucy said the vast majority of it can be reused & more expensive things like transmitters usually don't get damaged in combat. I've had a pretty rough run over the last couple of events (1 lipo fire, 1 other lipo die & multiple big hits from spinners) but once I've added it up it was less than half what I spent on the hotels for the events.