It all depends on where you live in the country,,prices differ so much. What I do is add up the material costs plus my rate and then divide that by the square meter area to be covered then you'll have your square meter price.

I have to agree with miller skimming is far better as sanding is not req and u get a better surface for painting

when taping over time the edges of the tape start to crack and would need skimming eventualy. This is a very common problem in new builds. Using scrim tape for the joints then skimming prevents this. I hope this helps.
Kind Regards
William

the last taping job i did was for a company and i was getting £12 m2 suppling and that was 4 yrs ago ,also you are better scimming as it doesn`t involve sanding your final coat before painting