A normal service consists of changing oil, filters and plugs, setting the tappets and handbrake and greasing the steering and propshafts. Certainly not that much work.
However, if re-greasing the birfields and front wheel bearings, replacing the coolant and brake and clutch fluids and diff, gearbox and t/case oils are included (which all actually should have been done a couple of times already) then perhaps that is not unreasonable.
So get them to explain to you exactly what they are talking about?
Mag ons ons kenniskry met lekkerkry aanhoukry.