You mean skins are $5/sq ft? That's expensive. If it's the whole panel (two skins and a core) that's cheap.Thanks for the great documentation. I am heading down this road for my DIY camper as well, but am having a hard time sourcing the FRP panels affordably. The local supplier wants around $5 sqft for the panels. In your research did you find any west coast suppliers?
Some people have used Carbon Core panels that have a plastic honeycomb core and FRP or plywood skins. They are made in China, and QC has been dodgy, but the cost is very reasonable. They are based on the east coast, so shipping adds a fair amount.