I'm not sure of the costs involved in learning to fly fixed wing but in the UK helicopter training costs about GBP 220 per hour including the VAT. Now, if it cost GBP 230 an hour in order to pay the instructor an extra GBP 10 per hour I don't believe that would put off a single potential student.
At its cheapest flying is still expensive. Before we start down this road most of us procrastinate over the money issue. In the end those that want to do it find the cash. Most of the people that I've met who fly helicopters are not rich - but they manage to find GBP 220 per hour, and they could find GBP 230 per hour.