lol what do you think youre paying the dealer 120$ an hour for?
all that plus their profit margin

with a large fleet of trucks you save big money in the long run by keeping the labor in-house
plus you control the parts inventory and can probably work out volume discount deals with the dealers on the parts, saving more money than the markup of the same parts installed by dealer techs

o and dont forget the travel fee
shop supplies
disposal fees
all marked up to turn a profit

if you have 1 or 2 machines even 10 its not worth doing the work yourself
but at 100 units youre looking at big savings