The Bank of England's inflation calculator has it that £40 in 1985 would be about £120 today.  My first British brothel I worked in was £50 for half hour, was in the mid 1990s when it opened and has gone up by the stellar price of £5 to £55 today, when inflation should have it at about £100.

Yes you can get more as an indie and thats what lots of us obviously have done with the rise of the internet, but few seem to charge more than £80 for 30 minutes from what I've seen, I think you'd have to be offering a lot of services and be very popular to justify trying to charge £100-£120 for 30 minutes and I always notice many that do, don't have a huge difference between their 30 min and their hour price , so they are clearly just trying to encourage people to book hours anyway.