In my club (Switzerland), as an instructor I'm on the roaster for
something like 10 days per year (students don't pay extra for having
an instructor). I do have to pay the full club fees, but I'm credited
50 CHF (=$50) for each day of instructing which somewhat balances the
club fees. I also get free 30h soaring time on club gliders (but I
don't use them because I prefer to fly my own glider). Club pays for
insurance, I pay for keeping my instructor license current.