Our guild does a silent auction - items are donated with a base price set. For 30-40 minutes bids are placed (and raised) on sheets with each item. At the end of that period, unsold items may be claimed by the original donor or the base price lowered and offered to the membership (it was rowdy this year). All proceeds go to the guild.
At our quilt show, we also have an area (blanking on what we call it) where small items may be sold with a portion (10-15%) going to the guild and the rest to the quilter - another great way to cull unloved items or earn some pin money selling handmade items. As a courtesy to the vendors though, we don't sell fabric bundles - those get donated to the raffle baskets.
Cheers, K