For some reason I thought I read 18'. But even at 22' that sounds about right, unless your incorporating walk-arounds and built in storage. Then odviously the price for materials would go up.
When I see custom builds and read the prices people pay for materials I feel very fortunate to have the ability to order direct from the manufacturer via my shop.
How much is the total price of the hull?
I wouldn't blindly send anyone the cost of materials, I'd demand a written contract with the ability to levy a lein if he doesn't fulfill his part of the bargin. You could easily pay for materials and he could simply sell your hull to a other party.
Got to protect yourself.