They explained it was memory-map, the software retailer, who set the charges of their own free will,
That's quite a funny comment from the CAA since it is the CAA who licenses the data to Memory Map !!
MM can indeed charge what they like and perhaps they (like most people) have no clue about aviation and really believe that UK pilots are rich, when in fact most are skint.
Or it could be that MM are factoring in the extensive bootlegging that goes on, with all their map products which are mostly the Ordnance Survey 1:25k and 1:50k stuff.
I have spoken to the CAA too and they claimed the problem is with the O/S and their ridiculous licensing policy (which itself
is ridiculous - e.g. the mandatory parity between the MM program date and the O/S map date).
You can get much cheaper charts from Jeppesen although IIRC not for a UK-only pilot. The whole Jepp CD for Europe (VFR Raster Charts) is about £200. You need Flitestar to view them, and currently there is no (legit) product (other than Flymap) which can run them as a moving map. However, for the UK, the CAA charts are much clearer.
The biggest problem is that the CAA has entered into these commercial deals and if they wanted to change this restrictive practice and e.g. offered them directly, or even free, they would probably get sued for damaging MM's business. But you can rest assured that anything from O/S will never be free
Another tack would have been for the CAA to make their own charts, not using O/S data. That would have been much smarter, and for that little backwater called UK would have been pretty easy.