Kensington and Chelsea current charge for Band D £1500. A much more affluent area than where I live, it really doesn’t make sense
The way Council Tax works is incredibly unfair as, as pps have pointed out, the most affluent areas usually have much lower council tax than poorer areas.
It's complex but, to put it simply, councils in "posh" areas aren't as reliant on Council Tax as they have other sources of income to balance the books. So they can afford to keep Council Tax low and, as they're often Tory areas too, choose to keep it low for political reasons.
If you're Kensington and Chelsea Council, or Westminster, for example, you can charge for parking and rake in millions a year that way. Whereas people aren't as keen to pay for parking in, say, Middlesbrough or Bolton or Barnsley - and if the councils in those places try to increase parking charges they get hammered by the electorate for damaging local businesses.
The Council tax base is a factor too. In wealthy areas you're likely to get more band D and upwards properties, whereas in poorer areas you have lots of small band A properties - who pay less.
Councils in less affluent areas also often have a smaller council tax base (eg the number of people who are paying full council tax) as more people qualify for exemptions on benefit-related grounds. It all adds up and means councils in poorer authorities have no choice but to implement the maximum council tax rise every year; while those in richer areas can freeze it for the political gain.
This has been going on for so long that councils like Windsor can raise Council Tax by 25% yet STILL have lower bills than most councils in less affluent areas. It's an unfair and regressive tax - and tbh if I was in Windsor I'd just be grateful I've got away with low bills for so long.