I'd be on for an occasional stay, but obviously I'd like to know more about the location. Five acres isn't huge and if it's on the hard shoulder of the M62 it could make for a less than peaceful night. The going rate seems to be a few pounds per person per night and I'd think that ten quid would put a few people off. You could probably say ten quid per pitch if there were couples and maybe more with families, but on the continent you can get a night in a bed and breakfast or a cheap hotel for not much more than a tenner so it needs to remain reasonable. Most people at BCUK meets seem to sleep alone so the per person/per pitch argument is, er, moot. Some people (yours truly for example
) carry liquid fuel in wherever they go, so I'd have thought that firewood could perhaps be an option rather than being included whether you want it or not. Having said that I think the bulk of the BCUK crowd burn wood just for the ambience, and I wouldn't want to sit around the fire thinking that everyone else was paying for it and I wasn't! I'm sure that reasonably priced firewood will sell well because on occasion I've even seen people dashing off to Tesco to get supplies.
Different local authorities have different rules. Sometimes there are informal arrangements and exemptions which can work well if not abused. Best to check with the authority concerned. I doubt that anything that was used all year round would be permitted informally.
The farmer should draw up a set of site rules, maybe something like the Scouts do for their sites. The potential for 'customers' damaging the place and filling it with rubbish has to be considered. I'm slightly surprised that nobody seems to ask for a deposit to be returned when the site is left in good order, but I suppose it would be difficult to operate such a system. If there's going to be access to the public rather than 'bushcrafters' only there will need to be arrangements for dealing with rubbish.