We have one. It is a but bigger than a JR50 but not as big as a KX65. They are a pretty good learners bike. Suits kids from 6 to 10. They are basically the same as the Gas Gas TXT50 trials bike that is still in production. It just has different plastics and a full sized seat. It has an auto clutch and a two speed gearbox. A clutch lever that allows the kids to dump the clutch.
There was one on Ebay in Australia recently that sold for $1350 AUD and was a bit of a bargin.
http://cgi.ebay.com.au/ws/eBayISAPI....m=120410139376