So far, the biggest single expense was the glass and epoxy. I bought from RAKA. So far, it's working great. The boards (redwood - not much cedar available around here in central CA.) cost less, but not significantly so. I think my next biggest expense will be footpegs. I'm going to carve a foam seat (from a $40 piece of foam) and build a seat back from strips. Overall, it shouldn't be too much. (Of course, I built a router table, bought bead and cove bits, a bench sander, two planes, a plane sharpening jig, a pull saw, a hand grinder, grinder blades, chip brushes and foam brushes galore, gloves, plastic bowls, stir sticks....and, of course, a new carbon fiber paddle for my wife (the boat's eventual owner.)