It is a daft pricing policy, but I suspect it's as much to do with the way the OS works as any excessive profits being made by MM, as I believe that the underlying CAA chart map data is still owned by the OS.
All it's achieved, as far as the OS mapping is concerned at least, is a host of download sites and hacking instructions so that more and more people can get the maps for free. This is nonsensical, as most would probably pay a reasonable price rather than spend hours downloading OS maps and faffing around editing the dates in them using a hex editor, not that this is how you do it, mind.........
Similarly, the costs of producing CAA charts digitally is very modest, as the data starts off as being electronic before it gets printed anyway. The only extra cost is that of pressing and distributing CDs, which cannot be more than a few pounds per copy.
As we are all required by law to have an up to date paper map anyway, distributing the electronic versions at a lower price wouldn't really impact paper chart sales a great deal, I would have thought.
VP