" I have sold PDFs as downloads in the past, but now that they are now about 10 MB each and the number of them will soon be over 40, I would need to assess the possibility of sets of maps being available on CD or USB drives. The price of such would have to be pretty steep, if for no other reason than to discourage counterfeiters and the headaches form such that would come this ol boy's way. So... we'll see. "
Sounds like you are dealing with some of the issues that we are regarding technology
. The Church I pastor had a huge "tape-lending" library and used to loan cassette teaching tapes to folks all over the world. No sooner had we begun converting to recording services on CD's about 4 years ago, and MP# format recording on "thumb drives" became the standard. It's kinda hard to keep up as I continue to gain a few years (smile).
I have a GPS, I barely know how to use, and installed some topo maps on it, of course the quality of maps I have on it don't compare to the maps you are producing.