I think auctions seldom bring in the value of a quilt. You need some generous donor with deep pockets who happens to like that particular quilt, and it is rare to come up with that kind of combination.
Raffles work better if you set a goal -- quilt to be raffled off after a certain number of tickets have been sold. Without that, *so* much depends on how good the organizers are about selling tickets. If they haven't taken good photos, advertised it well, priced the tickets well, given plenty of people lots of time to sell tickets, etc. the quilt may not earn the amount of work put into it.
As a quilter and a human being, I value my time. I would rather donate $100 to a charity than put $100 worth of materials into a quilt, lots of my time, and have the quilt raffled off for $100!