http://www.aukweb.net/events/You can see the prices on the calendar page. £5-6 is the norm. My local rides are £6 and include breakfast. Some organisers strike a deal with venues in order to use them, and include some free food.
There may be a few outliers, but I think they are rare. Sometimes organisers give proceeds to local causes. I dont think many are in it as a get rich quick venture.
The only ride that I think has grown considerably in price is the BCM. IIRC it has gone from £17.50 to £37 over 10 years. It did change slightly when all food was included (IIRC it went to £25). I dont know the history of the finances, and how it was funded 10 years ago, but even so despite the price increase, it still represents very good value in comparison to what is available in the commercial world.
Frankly, any event requires a significant amount of work, and I wouldn't begrudge an organiser having a bit left over by way of remuneration, whether it be the price of a few pints or a decent meal out. I dont think any of them can retire on it.