That's why I don't let my competition set my bid pricing and get a chuckle out of GC's and Owners that ask "Why does this cost so much!".
More time than I can remember our knowledgable Members here on HEF have cautioned newbies about the costs associated with owning and operating heavy equipment when the generic "I want to buy a dozer for my property but I don't have any experience" thread comes up. Some take the advice and some do not, the results are varied to say the least.
This is my take on hiring out mechanical work that is in the same lane as hiring someone to do land improvement or other excavating services on their property. Our company makes money on tearing down buildings, moving earth and putting pipe in the ground - not fixing heavy equipment. A good dependable mechanic is worth gold just like a good dependable site work contractor. If I wanted to make money repairing equipment I would open a HE repair shop.
Just an example but I would be foolish to take a crew that could earn $300-400 an hour doing what they do in the field and put them wrenching on a machine to save $150 per hour the mechanic charges. The $$ just doesn't make sense.
In my opinion I think a lot of the do it yourself types could save a lot of money, frustration and time hiring out the work instead of buying a piece of yellow scrap iron and do it themselves. However every man has the right to go to hell in their own fashion.