You also have to consider hotel cost, extra cost from eating out because can't cook in hotels. Someone charging 250 an hour is likely doing it in London where hotels charge exorbitant amount...especially central.
10 hours of booking a week is still several extra hours of advertising, communication, and preparation. And no one is going to work all 52 weeks of the year. It's more realistic to assume that for a lot of escorts it's about getting decent money while having a ton more free time than any regular job..rather than making ridiculous bank while working the same amount or even half that (booking time and everything else included) considering it can be a rather draining job to be on your best for every single one of those bookings throughout the year..for multiple years.
You are missing the point,
AVERAGING 10 clients is not a lot @ the 250 level and why does the extra effort you mention matter? If you tell me you're on 60k I don't go into your financial specifics. In this flexi-time business she could be seeing all those punters in 2 days and taking the rest of the week off, or working a solid week and taking 2 weeks off, whatever she likes. How she burns her cash is not relevant to the top line statement, it will be relevant to her motivation to work and in your scenario likely to push her to work more and earn more.
Whilst we may all have met SPs who order in expensive sushi and guzzle champagne we also know plenty who chow down McDs or pizza or fried chicken or uber eats. PLENTY of girls work from flats (many shared) where they can cook, many of us have been treated to sharing home-cooked meals. Canny quality girls at this price point working out of hotels may well have clients booking social packages with meals included. You can invent viable scenarios and so can I but they're not relevant to the top line.
The girls could be in a punting flat paying 1k per week for a room or they could be in a civvy flat in town with 3 girls sharing a 4k monthly rent, some might only work there and also be renting a room in Leyton for an extra 600 a month. How they manage their place of business is up to them and drives their need to work, those who have higher expenses fuck a little more.
Contrast with the "average" person paid 30k+ who's probably "working" 40+ hrs a week + commute time of say 1 hr each way, making 50 "captive" hrs and excluding personal peccadilloes around ablutions and making packed lunches.