A few of these events succeed in uncovering really rare antiques and collectibles. Most succeed in finding good salable merchandise. Please understand that these events can cost several thousand dollars to sponsor. They are run in the hope that enough merchandise can be taken on consignment or purchased outright to cover expenses and make a profit. Surf the web.
Many popular collectibles have web pages devoted to identification, preservation and sale.
Depression Glass, Old Ivory China, scientific instruments, eyeglasses, all kinds of porcelains and pottery, are just a few such sites. Many of these sites offer free or low cost appraisals. A few auction houses allow you to search their data base of sold items. This is a valuable reference source for more pricey collectibles and for antiques. Don't be penny wise and pound foolish.