This is what sort of puzzles me (and it is not to detract from the value of exchanging charts). On the one hand I see why people may not want to pay exorbitant amounts for various commercial/official charts - sure, expensive. On the other hand, though - do you really risk taking your boat somewhere according to a chart of unknown pedigree? This same forum is full of stories of people running aground, breaking things, damaging boats or worse - and having a bad chart is, in my opinion, is one way to make bad situation worse. Unless you plan to do "armchair navigation", of course, so chart quality does not matter.
Disclaimer: I have zero interest in paid charts from any source, and I would be more than excited to have more free charts available, since that potentially increases a number of people that may like my applications. But at what cost? Don't go out there with a crappy chart - it isn't worth even a single
call for a tow service
and soft ungrounding. Really.