I'm not completely sure, but I think Dan said the Cuben material only adds a little over $100(not including dye). I was going to have Dan build me A Cuben LBP36, I just didn't have the time to get in all the demoing I need. Dan was going to use like 3.6oz sqyd cuben for "extreme"(my words) durability. I think he said the tear resistance was like 321 lbs per square inch, for that weight cuben, again don't quote me on that.
When I get done with my upcoming 6 month trek a Cuben McHale will be back on the top of my list, for sure.