whoa!!!! please remember that "annual" refers to the inspection only.
Any repairs, new gadgets, etc, are not officially part of
the annual.

So how many hours does it take to inspect a Cessna 172. I do not rent the
plane, but have a 100 hour inspection done every 100 hours. Change the oil and
filter every 50 hours or less, Send oil to lab every 100 hours.
I do not think 55 hours at $70.00 is resonable for an inspection