XrayYankee wrote:
Trying to judge which will be more expensive at annual. A newer 172R or
S, or going very used, back to a 172M or N 1974-1979 era.

The "annual" will cost the same. It is an inspection, nothing more. I
believe we have hashed this point out extensively on this newsgroup. The
cost that differs significantly among airplanes, owners, and mechanics
is the cost to PREPARE for the annual. Since many owners only get things
fixed when their mechanic points them out DURING the annual inspection,
some owners confuse annual inspection costs with maintenance and upgrade
costs.

Preparing for the annual in a nearly new bird SHOULD cost less. This
will be offset by the dramatically higher acquisition cost. The older
bird receiving a steady diet of cash to keep it in good shape will
likely cost more to prepare for the annual. Again, this is offset by the
lower initial acquisition cost. I would be difficult to tell in the long
run which is the lower TCO. There are too many variables.

For example:
If you buy a plane in decent condition that was well maintained and
regularly upgraded (where old systems were replaced) AND you and your
mechanic are "fix it up cheap only when it breaks" kind of people, then
the cost of preparation will likely be very low - nearly zero. Then,
there is the opposite extreme. If you buy a plane that is run out, beat,
ill maintained, never saw a new part in 30 years AND you and your wrench
are very particular, then preparing for the annual could well exceed the
purchase price of the plane - possibly several time over.

Then, there is everything in between. Given all that, it is tough to
predict what the TCO will be in your particular case.

Good Luck,
Mike