From what I've heard, there is still a fair bit of the ?300-1000 work going on here in London - it didn't stop being a globally important capital city visited by plenty of zillionaires and famous people etc, after all. But I'd imagine the size of that section of the industry is much, much smaller now and having a perfect reputation (as well as perfect looks, perfect clothes and lingerie and a perfect apartment) is absolutely essential. I wouldn't try to break into that sort of price-range because I'm far happier where I am (and I agree - a wider client base means you get to pick just the nicest ones to see!

) and wouldn't want to feel stressed/insecure - but if you're already established and earning that much, then there's no reason to stop!
I can't help but feel that people still really underestimate the importance of establishing yourself when they start out nowadays. You've got to build up that great reputation and be creating a great blog and lots of great photo galleries etc. It really takes time! Even someone charging ?100 an hour in London could expect it to take a while to become ridiculously popular, even if they were seeing 5+ guys a day every single day which would be tricky since, well, think of all the clients who only visit an escort twice a year; they won't find you til maybe 6 months after you start. There are a lot of once-a-week guys at the 'parlour end' of things, of course, but once you get to maybe ?120-150+ you're looking at what is a significant amount of money to the vast majority of people.
Someone might even see your website in March and decide to save up to see you in July! So yes, I don't see much point looking at the earnings of an escort who's been working in one niche for x number of years, or the earnings of another escort in another niche who's been working for y number of years, and trying to draw some sort of conclusion. I know what I know about myself, and I hear all sorts of things from other sex workers about their work, but even if I worked for 100 years I wouldn't be able to begin to guess what a new girl might earn in her first week/month/year.