In essence, it is a telescope built onto a gun mount, which balances through friction as it swivels on an LP record.Total cost was around 400 Doller.You may be able to buy a similarly sized commercial telescope at that price these days, but you would not have nearly as much fun. The actual construction took a weekend, and it would be a great project to tackle with kids.
http://www.popularmechanics.com/home_journal/workshop/4286700.html