Harry Potter World of Hogwarts AKA Polly Pocket

I admit I am just starting this guide, also just starting my collection, but I shall share what I have learned so far.The World of Hogwarts collection is a series of playsets produced by Warner Brothers around or about the first two movies. I believe 2000 is the year of the first set release. They lasted through the first two movies, but I can find no playsets for the third or fourth, so I believe the series has been discontinued. This does not stop my kids from loving them!At the center of the collection is a large Hogwarts castle playset. I say large, but it is about 12" tall. The base contains electronics and gears which operate the moving parts and sound effects. The castle folds out like a dollhouse to reveal many rooms. The center portion contains the owlery, Dumbledore's office, an owl landing room on the left with Hedwig in it and the girl's bathroom on the right with a large club in it and the great hall. Hedwig and the club move and make sound effects when a button is pushed. Similarly, the side panels each have a classroom and another room with a moving, sound-making item. In the bottom, two dungeons fold out with moving objects, but these don't make sounds. In the back, a folding door reveals an empty classroom with the Mirror of Erised on the wall.This playset came with the most figures - Harry with a lantern, Ron, Snape, a troll, and some tables. It may also have gee with a suit of armor and/or invisible Harry. The figures are only about 1" high.The lantern Harry is particularly important as he has a magnet in his base. It is this figure (and only this figure) that circles the great hall when placed upon the moving track.Other playsets can be enjoyed separately or connected to circular gears on the Hogwarts castle. If you connect them to the gears, the smaller playsets each have parts that move as well.The playsets include: - a smaller Hogwarts castle which represents the hidden area behind the third-floor corridor ... contains fluffy, a flying broom in the keys room and some other items. This set may or may not have gee with figures.- Ron Weasley's house from the second movie. This playset gees with Harry and Ron figures, dressed in street clothing, and a three-headed figure that is a pack of garden gnomes.- Hagrid's Hut. This set gees with Hagrid. Not sure what else.- Quiddich Field. This set came with a flying Harry and, I think, a flying Malfoy.- Platform 9 3/4. Not sure what this set came with, but it was half a train and a small platform.- Finding Them -Finding these sets is not easy. For some reason, most folks on okay list these as 'Polly Pocket' sets, even though they are clearly much smaller than standard Polly Pocket toys. Others know they are called 'World of Hogwarts', abbreviated 'WOH' but these folks have an inflated opinion of their worth.Most of the sets seem to be missing one or more figures and requests for figures through the Want It Now feature on okay have resulted in very few answers.Oddly enough, the packaged sets don't seem to sell for much more than the used sets, even though they contain all the figures. Then again, I have yet to see the original castle - the centerpiece of the whole system - sold as new in package.Good luck :)