There are no set rules, or guidelines for pricing and some will say, as little as £7 to £8 per hour with a straight face.
We aimed for a return of around £30 to £35 per hour for carpet cleaning and around £19 to £24 for house cleaning.
We never quoted these prices to clients, prefering to give prices, on a, per job, basis.
You have to decide your minimum acceptable rate and stick with it.
I know of a young female who started up and her first job was similar in size, to your ( d ) type.
She quoted an astonishing price , of just under £400 and got the job, spent 3 days working alone and was imediately asked to quote for other work.
rob m