Mike
I am aware that the CAA get much of the data from elsewhere, but equally I would suggest that if a mapmaker wanted to generate a map of the UK which contains the (rather low) amount of detail that the CAA chart carries, they wouldn't need to pay anywhere near the sort of money to Ordnance Survey which for example the AA (with their road maps) did their massive out of court settlement for.
Nobody has copyright on geographical data. The stuff has been there for many millions of years
You can generate 90% of what is on the chart from public domain sources. Nowadays you could do a deal with say Google or NASA for high quality photographic imagery. In fact if you flew around and photographed the place yourself you wouldn't need to pay anybody a penny.
The stuff one really needs for a VFR aviation chart is an obstacle database, which needs to be reasonably up to date. The CAA gets (or buys) that from the MOD, I believe.
The royalties the CAA pays on their VFR charts are absolutely minimal, or they should be.