+1!
When playing, I don't have the individual ball costs in mind but rather a steady admission fee, "green fee". This is the fuel of WGT, a steady income.
As a Master, with SD balls, I once counted the sleeves I bought and the rounds I played. This included the share of balls which I lost at that time. From that, as a rule of thumb, a nine hole strokeplay round may cost 1/10 of the price of a sleeve,
6 crs with Tour SDs, 1 cr with B-ES, 60 crs with top MAX balls (maybe a tad more for those low durability dot balls). Of course it varies with balls lost (probably considerably more in CTTHs).
Good thing to me is that ev1 can determinate the costs, i.e. the fee, for himself. You
want less, you pay less (starting at zero); you want more, you pay
more.