No matter what, it is YOUR RESPONSIBILITY to agree on a price....If you simply agreed to $10 an hour, that left the door wide open....I am not saying he is right for doing this, but that you agreed to it plain and simple...You said it is a $150 plane...did he install the radio gear and the engine...If he built it, covered it and did the engine and radio install, then I can see where someone such as myself that has to do the best I can to do a perfect build would easily get 60 to 70 hours in it.......covering alone is sometimes the biggest pain and a major time consumer...especially if the graphix are pretty detailed.....

I am on your side, I think he way overcharged you.....but you agreed to it