Don't forget your interest costs, assuming you will borrow the money.
Even if you pay cash, you lose the investment income.

Many buyers end up spending extra amounts on the first inspection
because of items that have been neglected. Allow 10% of the purchase
price for this.

I can't over-emphasize the value of a very thorough inspection by
someone familiar with the breed and no financial interest in the
outcome.

Insurance is significant: you'll need to get a quote on that.

There is seldom an economic reason to own an airplane, but there is
something wonderful about owning one and flying it for the cost of the
fuel.