Summerhouse- What is a fair price to pay?

most fellers in the trades would be expecting to earn at least 200 a day.
Have you got a proper base laid?
It depends on the package and how well its designed and what snags come up.
I put up a timber section summerhut in about a week by myself mainly, but there a few times when i needed help.
Also there's other things like guttering, presumably you need electrics.

You might be better getting a price to do it all, rather than a day rate.