I think it is a good opportunity, but you need to be cautious. Do you know this person, are there friends who know this person and his reputation? Julie R. gave some very good advice. Start slowly, but up front get details - such as how many quilts would he expect, what type of quilts, would you be making one type of quilt always, or could you make a good variety of quilts, and get a price range for what he would be selling the quilts. Plus GET EVERYTHING IN WRITING. I wish you luck as it sounds like a great idea if he is truly interested in selling your quilts, but I also think that 50% is a bit high, even if he does supply the materials. Let us know how it works out.