Currently, the ABV of a beer is often a remarkably good guide to its price, simply by reading the percentage figure as if it was an amount in pounds.
So 'ordinary' bitters, with ABV values ranging from 3.5% to 4.0%, might typically cost between £3.50 and £4.00. Premium lagers, with ABVs around 5.0%, tend to cost closer to £5.00.
However prices in some parts of the country of the country can be significantly higher. See my second post here, from just 12 days ago, for examples of prices in one of my favourite pubs in central London:
https://www.theanswerbank.co.uk/ChatterBank/Question1747826.html
Prices in J D Wetherspoon pubs can be quite a lot lower though.