There are jobs that would allow myself or others to charge £200+ an hour, I considered one that would allow me to charge £150 an hour, great money, insane hours, and rarely being home. I've got friends in cyber security and they can charge £300+ an hour for consulting.
I'll wager, however, that they have a huge cost of sales (primarily in time, which can look like sunk cost), and that the number of hours they would actually sell would be relatively low - or at least the pattern would be bursty and fallow periods will be stressful. Some of these, you also need to spend a lot on R&D, and burnout will follow.
I suspect that one of the advantages of WG is that the work comes to you, so long as you maintain a decent online offering.
I met a woman through WYP who was considering starting out and had a friend who's a WG. As she put it:
- the first guy pays for the hotel
- the second guy is pocket money
- the third guy pays for the extra laundry
- the other(s) are extra pocket money
Still, you need to have a credit card etc to get going like that - and even with a WG friend she had not considered how many towels and bedcovers she would need and have to launder.
Sadly she won't let me break her in and is trying to stay Civvie - good for her, though its really hand to mouth for some people.