Davey, I think it's a little misleading to talk about salaries of £90 - £150k. While these amounts are eminently achievable after a fairly long time in the job, it's probably more useful to talk about the kind of money to be earned by a relative newbie.
As you suggest, if a new pilot begins with a turboprop operator, he can expect between £17 and £25k. If that pilot is lucky, and gets his first job with a low-cost jet operator, he might expect £30k or a little more. However, many, many professional pilots begin their careers flight instructing, air taxiing or night freighting, where wages may be between £8k and £15k.
The guy who gets that jet job straight away might expect command within 5 years or so, in which case he might be making the £90k you mention. However, the guy who starts down the FI route might take 30 years to get into a job where such salaries are possible. As for £150k, there are very, very few in UK aviation earning that kind of money - and their age and seniority mean that they probably won't do it for long!
The majority of UK pilots are probably within the band £40k - £70k. That's not to say they can't earn more, but, for many, their personal peak will be within that range. Those are the kind of ballpark figures I'd be telling a wannabe.
Scroggs