At one time this was the holy grail of plate collecting. The Hummel 1971 Heavenly Angel annual plate brought prices exceeding $2,500 back in the early 1980's. Today's prices for this plate usually range between $50 - $100. Why such a decrease?
Economy, changing tastes and Ebay are some of the major reasons, but I feel that ulitmately it is a matter of supply and demand. Antiques and collectibles tend to be generational. In simple terms items that people collect have a life span that typically follows that of the collectors. Hummel plates (and for that matter Hummels in general) were collected by people who are now in their 80's. They started collecting in their thirties and forties and now as they begin to age they are divesting themselves of their collections. This creates an inequity in the collecting field that did not previously exist. More plates and fewer buyers has created a huge decrease in the value of this type of collectible.
So as a buyer and seller of collectibles you should be aware of these buying cycles. Realization that this type of supply and demand curve exists for collectibles can make you money. What do you think will be the next group of collectible to die in value? Which group will be the next to escalate? Keep your eyes and minds open to the changes in supply and demand.