Long Term Motorglider Launch costs

Several years ago I was helping Wilf Krueger K2 strap into his DG 800B motorglider.
He looks up at me and says "here goes the most expensive tow I'll ever buy"
He smiles and takes off.
I'm curious from those in the know, how much did that launch
really cost him?
Over say 25 flights a year over 10 years how much roughly does it cost per gasoline powered motorglider launch?
Including ALL maintenance and fuel and parts. And hands on time to keep the engine running at say 75/hr labor. Extra annual inspection costs too.
That's 250 launches
In my LS3a my average launch seems to be about 65 bucks.
65X 250 launches = $16,250

What are you motorheads really paying per launch over time?
Do you try to keep track?
Or is it just one of those necessary life expense's you really don't want to know the total as you'd pay it no matter what ?
Thanks in advance
T