I'm sorry, but amongst the several things in your post that don't make sense the last is the silliest. Firstly, the valuations that are used for council tax come from 1987 or thereabouts, current market value has absolutely nothing at all to do with it, and secondly, the council needs a certain amount of money in order to deliver the services that the local residents vote for, and that has to be divided amonst the houses that are there, and the prices don't come into it.