Just to give you an idea of time.
I cleaned 60 dining chairs with my portable a couple of years ago.
( Base and back upholstered )
It took me 4 hrs from start to finish.
I charged £3 per chair.
With the fixed seating measure the total length, and charge a price per foot length.
Pricing fixed upholstery is difficult ? £3 to £4 per foot ?
perhaps best to try work out how many hours to complete the lot and work it out on your day rate ? assuming that you def want to get the job ?
regards
Chris