Calm down dear, it's only an internet forum!
I really do get it. Really. I promise! Let me try again to explain...
£236 is the going rate. It's the going rate for the IoW festival CV field. That's all that matters.
You either buy or you don't. You have a choice. Limited supply, big demand. It may not be fair (in your opinion) but it's the price they set. You choose to buy or you don't. If nobody buys, as has been mentioned previously, the price comes down. If they sell all the tickets, the price may well stay the same or even go up.
Whether or not it looked 2/3 full doesn't matter. They will have a licence for x number of CVs. No more. If that only half fills the field then so what? That's all they are allowed to sell.
If the festival was massively oversubscribed - do you think they'd keep the prices at £220? Absolutely not. The price would go up, and up, until ticket sales started to drop off. Then they'd level off.
£220 is the going rate for the IoW weekend festival ticket. Not all the tickets sell. They cleverly match the demand with the ticket price for revenue maximisation.... with little tempters like early bird tickets to get a bit of cash flow up front...
Again - supply and demand. In this instance - less demand and more supply - this keeps the cost of the ticket at the point it is (and absolutely not subsidised by the CV tickets!).
This, my friend, is economics.
You may not like it, but that's the way it is. You have exercised your right to choose.
Like flight prices increasing during school holidays. Supply (limited) and Demand (high) - prices go up.
Or ferry prices during the IoW festival weekend.. the prices go up, with small discounts outside the popular travel times...