From what I see, the way quite a few schools operate is fairly underhand, they charge for a flight instructor then take a massive cut of it for themselves, sometimes nearly 40 - 50 %
I suppose Heli instructors deserve a little better pay, after all,
to jump through all the hoops costs a massive amount more then fixed wing pilots, to even start the Fi course requires more hours also genrally fixed wing pilots will get more hours in flying cross country etc.
People don't like to hover in a field to long and gift vouchers will only ever really be half an hour in a helicopter as opposed to at least an hour in fixed wing.
On top of that, you guys can move on to relatively secure well paid jobs in the airlines with Unions etc,
We just get shafted from one job to the next,
(But it is more fun, and that is what employers take advantage of, knowing you love to fly, they think they can get away by paying you crap wages unfortunately a lot of them do.)