We did a 36 x 12 two bed a couple of weeks ago.
Complete deep clean: Carpets, curtains, walls, ceilings and all fixtures and fittings (but not furniture)
It took 2 cleaners about 3 and a half hours and we charged £150
That's about £21 per hour, per cleaner, but for a standard general clean that might only take an hour or so, we would charge slightly more - about £50 - to make it worth the effort of sending two cleaners.