I think there are several things going on with antique/collectible prices. First, the internet made a lot more information readily available & facilitated sales. People saw what things were selling for & dug through their attic/basement to pull out items that otherwise wouldn't have made it into the market, increasing demand which lowers prices. Second, the massive increase in the amount of high quality fakes has made people gun shy about certain areas of collectibles. There are a lot of fakes in the pottery, glass, coin, etc categories that are difficult for the casual collector to spot. Rather than get burned they just don't buy. Third, there is a whole generation of collectors that are at or near retirement. Those people collected things that were relevant to their generation. As they die off there is less demand for those items AND items are released from their collections. That increase in supply causes a drop in prices. Finally, people that are collecting want things that are relevant to their generation. While there are some exceptions in general people don't want their parents collections. All of these things(& more) add up to a market where the old stand by items are dropping in price & new categories of collectibles are being born.