I agree, that many people want to take advantage of your skill. Everyone is looking for a deal, my husband is Htg/Air conditioning teacher, many times someone asks him to come look at there a/c, he fixes it and they'll ask what do I owe you, he says whatever you think its worth, they hand him a $20 which doesn't even pay him gas for him to get there. Taking advantage of someone with a kind heart.
I usually give people a good deal on a quilt if they are my friends. But my husband has his brothers neighbor, people he doesn't know, and once this happens, they expect him to keep their furnace going for 10 plus years.
Moral of the story, up front say $250 plus cost of materials... (that is what I estimated for a t shirt quilt, start to finish)
kind heart is great, but it doesn't pay the electric bill.