I have built several boats at home. Not lately tho. a few years ago, resin was $600 for 55 gal. Enough to do two 400-450 pound 18-19 ft. boats. The mat and cloth was $2.50 - $3.50 per pound, depending on what kind you use. you'll need a drum of acetone too. used to be $250. and gel coat. and balsa. and mold release wax. and paint brushes and rollers and squeegee. depending on where you live, there may be issues with code officials. I got in trouble for doin it when I lived in Havasu, but not here in Oklahoma.