I am on the organising committee of a MV event overseas which has been going for 33 years. It takes place over 7 days, not big in vehicle numbers but those who do turn up often travel 100's of miles to get there, in one case thousands of miles. It does not take public admission money, but they are welcome to come and see the vehicles. We have trips out over several days with organised visits, quite often schools where we are warmly received. The ultimate day has a drive through the local town to a display venue with all the vehicles lined up for an aerial photo, and a swap meet takes place. In the evening a presentation and auction, which is for donated items, and the income agian going to support the event. We charge an entry fee of equivalent to £10, this covers administration cost such as printing, phone bills, etc. The local council over the last couple of years have recognised how many visitors and increase of trade is brought in and have given us a grant under a tourism scheme, with this last year, every registered participant recieved a cap with embroidered logo, and a coffee mug also with logo. The grant also paid for other requirements, such as a site office for the week and an aerial platform to take the photos by. Discount vouchers from businesses in the area were received.
Now this event is for the owners and enthusiasts and no one quibbles about a fee. I have been going to War & Peace since before it was known as that, I look at it as a meeting of enthusiasts, not there to show off to the public, therefore the entry fee is in fact a "camping fee" and for 8 days, pretty good value.