When I marketed to this market I would try to split for logs pieces that are about the size of my fist in dia. and 14-16inches long. I would bundle 15-20 in a pack and try to get $15 for the package.....Nylon bailing twine makes good cheap bundling straps.
That is a licence to print money. We have to burn whatever the campground operator supplies, usually green poplar, as we are not allowed to bring our own in. We also can't bring in good firewood from British Columbia because of the beetle.