True, cost is a factor...
You're right Don, I wasn't really thinking of the cost factor. When i'm doing my kayaks, it usually takes about 1.5 gallons including all of the filling and seam work to do a 16' to 18' kayak. I'm also trying for the most transparent finish I can get so that the wood grain shows through. You are going through a lot more resin. Epoxy would add up to $$$ with little real benefit.
BTW, I don't know who you use as a source, but I've been using US Composites and their prices seem to be pretty reasonable. They carry epoxies and esters along with all of the various types of fabrics.
Happy grinding!