OP where are you based? You’re gonn get different rates in different parts of the country. How big is the deck going to be? Height, steps, balusters, hard or soft-wood.
Ps. Don’t forget membrane, end-grain sealer….Spax screws ( wirox, coated 15 year warranty ) £45 per 1000 approx. Cheaper screws available… What bearers & rafters etc. C24?
Many factors to a deck…one man’s deck won’t be as good as the next man’s..ask him how many he has built and look at photos…