Sounds like a good way to save a few bucks.

Normally I pay $1.599 at the local gas station. This trip was special
because
I used actual avgas, which I think was $2.79. I try and use avgas
every once in a while, but not too often.

Then your actual cost was more than $40.00, still fairly cheap for
flying.

I have a fund for the inevitable engine overhall, but I place a constant
amount per month (not per hour) because it seems likely I'll reach a
reasonable yearly limit before a reasonable hourly one.

Everything I like to do costs money, one way or another. Did you get
your $40.00 worth?
Wayne

I like to fly.