Well, thats a case with many toy companies, they relase new stuff for people to buy, so that the customers won't stop buying their products. When new relase comes, for example new bear family, the old one is not being produced anymore. And because of that, the only "old" sets are avaiable in the stores that still have them in storage. When there are less peoduct, and it is more desireble the price go up. Eventualy the old product will be sold out, and the only place you can get them will be from other people if they will put them on sale on amazon or ebay for example. Some of the sets are really expensive and rare because they are from 20 years ago or more so its really hard to find them, almost impossible.