All fish clubs, well maybe not all but most, have auctions every few months as a fund raising event to pay for speakers. They rent a space and hold a fish auction. My own club uses a community center for it while one of the nearby clubs uses a VFW hall for it. The typical split on proceeds is 25% to 30% to the club and the rest to the seller. For me that means that my excess fish, the ones you are talking about trading for filter wool and such, give me back enough cash to pay much of my fish food bill. It also means getting fish that are seldom seen elsewhere at a real bargain price. Would you rather have my surplus rare livebearers at a dollar or two each or pay Aquabid prices plus shipping for the same basic fish and have them arrive a day or two after they are first bagged up? I like to get mine locally at much lower prices and in far better shape. The club wins because the space they rent is paid for before the auction is even half over and the sellers win because they get cash to use as they see fit for their hobby.
Typically fish club auctions are held and are open to anyone at all that registers for that sale as a buyer or a seller. I go to neighboring clubs to sell some of my surplus and also to buy things at those auctions. I cannot say that I always come home with cash in my pocket because I act as a "runner" during an auction. That means that I deliver the fish bags to the buyers but, more important to me, I get to see all of the bags of fish before they go on the auction block. If I decide to bid on a bag of fish, you can bet that I really like what I see in that bag. The down side is that I buy far more than I would if I simply sat out in the audience. (Everything we do has positives and negatives to it.)
they are very cute! Some are normal colour and the rest are black and spotty. 
Thanks for the suggestion, though!
