You can get one of these 6-wheeled crazy boards at Freebord’s website for around $200
A freebord is a type of specialist skateboard designed to closely simulate the behavior of a snowboard. They have 6 wheels – two spring locked castor wheels on the central axis, and four slightly raised conventional wheels. The central wheels are able to turn freely in all directions, which allows the Freebord to slide laterally as long as no other wheel touches the ground. By exerting some pressure on the edge wheels, the Freeborder is able to control the board. The central wheels thus mimic the deck of the snowboard, while the outer wheels mimic the two steel edges.
Older Alpha series decks featured kicktails and were of a longer length (100 cm and 112 cm). These have now been completely replaced by the newer models which are much lighter and more maneuverable. -Wikipedia