I don't spend a lot most of the time, but then I splurge.
I guess I spend about £3k a year on hobby related stuff... roughly £300 a month... more than I had ever really considered what it would be.
Latest spend was a Varjo Aero VR at £1000
Same as me.
Using my bike/kayak will cost only fuel.
But sometimes I'll need new parts. Go on a holiday. Even new bike/kayak.