I was contacted about 2 weeks ago from somebody wanting to use one of my pictures for an educational game they are making. they said they will pay me. i am not sure how much to ask for, and they said they werent sure either. What would be a good estimate to ask for? I'm afraid of asking for too much and they just forget the whole thing;but this could make alot of money in the future and I know I would get upset with myself if i just basically gave this person the picture.