Kits are available through Musicmakers Kits and Lark in the Morning (Songbird, I think). Both are fine, but you can find some finished instruments for 50 to 100 more. Most of the kits I've seen have made very decent dulcimers. But, a good kit will probably run you $150 plus....and a decent 12/11 can be had for $250.You might want to try the plans in the Phil Mason/Mel Bay book as they are really simple and involve only very basic woodworking skills and tools.
Lemme know if I can help in some way.
Spaw