35-40 $ for a case of 125 targets 12-16 $ for a box of ammo
So, a buck per shot is the cost, at retail prices.
470% mark up, but that doesn't cover the cost of hired help, taxes, mortgage, power, etc.
Businesses and very often, clubs, get significant discounts, depending on how much ammo/clays are purchased at one time or if it's an ongoing order.
My club only sold ammo to those who "forgot" to bring their own. The same situation applied at all of the surrounding clubs we used to travel to.
Some of the clubs in the Lower Mainland, such as VGC, which is now on a different property, had all sorts of ammo options for sale, as well as components, such as fresh dropped pellets, too reclaimed pellets, new cases and reclaimed cases, primers, powder, but suplied reloading machines for their club member's use.
Shooting trap/skeet has never been cheap, and it's more expensive now than it was in my days.
That's sad, because it can be a seriously addictive sport.
When I last shot trap, there was the cost of practice, which just covered the club's costs, of power, trap machine maintenance, clay birds, and ammo. If we loaded our own hulls, 6-8 cents per shot and 3-4 cents per clay bird, depending on whether we used reclaimed shot or fresh dropped.
Then we had "meat shoots."
We were encouraged to bring our own ammo, reloaded or factory, within the regulations. Meat shoots were money makers for the club.
The profits from the trap shoots kept the lights on and paid the taxes on the property at that time.
There were five shooters per set, competing for a package of steaks, pork chops, or chicken.
Value of the prize was around $12, which was a "family pack" of meat back then.
We charged $5/round of five birds, and usually there was a clear winner, but often "shoot offs."
Those were profitable shoots for the club. All of the labor was volunteered by members, so for every dollar they spent, they made another.
I don't know if the OP was calling a round 25 shots, as in five from each station, or 5 rounds, one from each station.
If it's 25 rounds, it sounds quite reasonable at today's prices.