Most of the props that show up on ebay aren't props actually used from the show. It's a shame, but true. I wondered myself a while ago what happened to the costumes used on the show, but I don't think anyone really knows. They were probably recycled back into the ABC stock, or are in a storage area somewhere. If they were around I'd imagine Jim Pierson would be auctioning them off for big $$ at the Fests.
Too bad most props and stuff were left to rust and rot. Nobody thought people might someday pay a fortune for them!