My other hobby is roller derby, and it's a LOT more expensive:
skates ($100 for a decent pair, $300+ for a pair that will last you awhile)
pads and helmet (again, $100 if you want them to be sturdy)
Plus team dues, uniforms, insurance, etc. My caching habit is a lot cheaper than my crashing-into-girls-on-a-rink habit, for sure.