General Costs

What are some of the costs associated with owning an airplane?
Particularly, I'm partial to a single engine four seater probably of
the Mooney's
I'm not to leary of costs such as planned/unplanned maintenance but
admittedly understand nothing of the FAA regulations involved. Is
there some kind of annual/bi-annual checkup you have to have on the
plane? What are pitfalls to watch out for? For instance I've heard
just because older planes are cheaper doesn't mean their TCO is. Is
the high TCO on older planes because they're just old or does the FAA
have more stringent guidelines in their inspections/checkups whatever.

-Opey