I have donated quilts etc for various fundraisers over the years. Some things did go for less than the materials, others had bidding wars to win them. While I would agree raffles seem to do better than auctions IMO most people go to get a bargain as well as support the cause. I donate because I want to and don't equate the cost of materials with what the cause gets for my quilt(or whatever). Whatever they get is more than they had before. However if it bothers you then donate money rather than a quilt. I think the question you have to ask is would you donate the cost of your time and materials to this particular cause if you hadn't been asked to donate a quilt.