I just figured up the first year's annual operating costs on our Aztec.

Using an average fuel price of $2.75 per gallon, we flew, hangered
(partially heated), insured, and maintained it for $188 per Tach hour,
slightly less per Hobbs hour.

This does not include any upgrades or improvements. All maintenance is
owner assisted w/A&P sign off. An $11 per hour per engine charge was
included (AOPA's figure). Also included was our first year insurance cost
which was reduced $500 upon renewal this year.

Jim Burns