This argument has been going on longer than most of us have been in the sport!
My take on it is:
Unlike the US, the number of shooters is quite limited. There is only so much 'pie' to be had and there are quite a few grounds trying to make a living from clay shooting.
The cost of running a shoot, even a straw baler, is not insignificant. The UK legislative landscape means insurance and noise and NIMBYS and land rent and and and. If you want a clubhouse and facilities the cost skyrockets. All this comes down to tight margins for ground operators. Some people seem to think that ground owners are rolling in money. I know a lot who barely make ends meet, eeking out a living by working their arses off. Some have a decent income but they have invested millions.
What this means is that grounds want to get shooters around the stands and paying for each target shot. Like it or not, the have-a-go lot, the guy and his mates who go shooting once or twice a month or the guy who never enters a competition make up a LOT of a grounds income.
Over a year the cost of a target at a shoot ( an 'organised, regular ground with ground staff and a clubhouse and an ePos system and decent traps and insurance and electricity on site ) is currently running around 30p per target. ( the margins are about the same as most other businesses ) So grounds are charging about £35 per hundred targets and making a whole £5 profit off you for an hour-and-a-half to two hours entertainment. To be frank it's laughable. On a Sunday, getting say 250 people around your ground ( a busy day ) you make a grand. As a business that's not exactly rolling in it is it. Monday to Friday numbers are way down on that!
Running a competition is, if anything a cost sink for a ground. 10 to 15 staff for the day, even uni students want paying for sitting in a rainy, muddy field when it's 5 degrees out and the wind chill is another 5! There's fees to the National Organisation or FITASC or anyone else. £35 to £40 for a mornings entertainment is reasonable but jack the price to £60 to £70 and the income drops off. A lot of people simply stop shooting as much.
I would say, given that most competitions at National Level are over subscribed you could happily charge £1 per target, You'd get the more professional shooters in and cull the field to the really dedicated ones.
But an additional £5 - £10 per round of club level competition is going to chase the mildly competitive shooter into either not competing or shooting B/O and B/O pays the ground owners bills.
I for one would simply stop shooting Comps, I can track my own averages, shoot with mates and we can run our own round much as people do at golf. It's not that I can't afford it but I don't see the point of paying £5 to some sh*t hot shooter just because he is on the ground at the same time as me. The ground owner is happy as he is turning over targets.