My XH paid £160 ish for outcalls (where they come to you
) booked through Adultwork. From my review of his account
he could have got women for £100, but not much less - and that was in Birmingham. So I'd say no way for £40 in London.
Anyway, the amount hardly matters except to confirm he is still lying.
He's also lying that it was 10x and 5x. (Nice round numbers there!)
If you are a habitual prostitute user through multiple relationships, why would you keep count? My XH was going about every fortnight on average - he wouldn't have been able to put a number on it. If I asked you how often you had your hair done last year, you'd give me a good estimate but I doubt you'd be right. And you'd have no reason to lie!
If it helps, my XH had been using them for at least 10 years but I expect 30 odd. I got the all clear on tests - and I even think he'd used street prostitutes as he got a curb crawling letter 
So
don't assume the worst x
As to the future... it's really not a sex addiction. It's a selfish arsehole who managed years of sex whenever and however he wanted without effort, without risk of being caught (he thought, and was right for so long) and without guilt.
You don't have to throw him out TODAY. You are in control, make your decisions in your own time. Though he can keep his disgusting scummy self away from you!
But to the poster who said he doesn't love you any less today than 6 months ago...
He also doesn't respect you, love you, care about you and your health any more today than he did six months ago.
If he simply chooses to do this - why would you stay?
If he's an addict - he won't stop, so why would you stay?
If you have the pleasure of looking at adultwork
as I did, you will see there are 1000s of women on there. With multiple reviews. There is a market. It just doesn't sound likely to me that that reason is so many sex addicted men.
Yes, no-one here can say definitely that your husband does not have a sex addiction. What we can say is that it's far more likely that he's just a selfish cunt he discovered he could get easy sex without you ever knowing. He thought.
Take it easy on yourself 