Actually I do think YABU, sorry. That man has to make a living the same as everybody else and he makes his living by charging for people to go on the merry-go-round that he maintains.
When you've got 3 dcs like I have, you soon learn to avoid fun-fairs!!!!!
Plus I don't particularly like the sort of people who hang around fun-fairs anyway. A bit unsavoury and seedy for my liking.
The best thing to do is find somewhere like West Midlands Safari Park where you pay £6 for a childs bracelet that enables them to use all the rides (age appropriate of course) all day - excellent value for money