Biscarrosse is a club. A non profit association. I don't know about Lake Como. Every club in France is allowed to sell short flights at whatever price the market will bear. Up to ten percent of their income can come from these. There are rules about who can do them and how long they can be. The hourly rate is for members who pay a subscription. Biscarrosse charges a lot more for a short flight Pro rata than the members rate. You can rock up to the hangar, get a ride, pay, leave. No annual subscription. Helps to pay the bills, no commitment to carry on. It wouldn't surprise me one bit if Como does the same. If that doesn't suit you then you are free to take your custom elsewhere. So Como put the price up? I suspect that's because they were losing money. You should have flown the first time you went, when it was cheaper.