I've always thought that the 6p a clay when buying by the box from a local gun shop gives no clue as to how much a big commercial clay ground pays when taking deliveries by the wagon/container load. I would not be surprised if the price to the ground was as low as 2 or 3p.
Doesn't mean that a round of 100 sporting has a cost of £2 or £3 for clays as there is considerable storage & handling costs to add to that figure before the things end up in the air for our pleasure and/or frustration!
Sadly there is also VAT, Corporation tax, Council Tax (even on your car park at your shooting ground), batteries, wages, income tax, Traps, Trap parts for service and repair (motor and gearbox £300) Heating, lighting, battery charging, Clay storage, handling machinery....need I go on ?
How many shoots would give you a VAT receipt for your entry if you asked for one ?
How many grounds have first class facilities ? 3 or 4 at most
Many have some sort of portable loo in the corner of a rough car park, many have a drive way that needs a 4x4 to drive down without causing damage to the average car yet they all charge top dollar for us shooters. 6 or 7 times the cost of a clay seems somewhat excessive to cover overheads when these are third rate.