RE: R/C the most expensive hobby ?
I fly full scale which is mega $$. I maintain a bunch of Pc-12's, you guys would not believe the cost of some spare parts [X(]
I also sail skiffs. These cost a lot of $$ to be up the pointy end of the field. A lot of the cost is things such as money spent on travelling away for a few weeks to race. AS for the cost of keel boats.... lets just say if you have to ask then you can't afford it.