I am sure they want to be fair and considerate of your time, regardless of your skill level. It still takes time, money to buy the tools and etc. They are trying to not to take advantage of you. Perhaps you could only take part of it when they offer. I am sure you could use the money to buy more quilting items. Another suggestion is take the money and let them know you will make charity quilts or put it toward a raffle quilt. You know pay it forward! That way everyone wins.