I think it depends on what type of Fair you're talking about.
Our previous school holds a traditional craft fair (or fayre!!) near Christmas each year. There's a fee of £10 per table (usually around 25 stalls) which is money collected directly for the school.
What's actually sold depends entirely on the stallholders. We had something similar to the £7 chutneys, but also cards, jewellery, sweets etc at varying prices. That money belongs to the stallholders.
We also ran a cafe selling cakes/drinks/soup etc which usually raised another couple of hundred. Plus a raffle.
At our current school, the Summer Fair consists of games etc made up and run by the children. This includes welly & wet sponge throwing, various guessing games, apple bobbing, and similar - usually with as much mess as possible!
All money raised goes to the school. I'm not on the PTA here, so have no idea how much money it raises.
Both events are completely different, & both enjoyed very much.
Another point to consider is who is anticipated to attend.
The Christmas Craft Fayre was very much for the general community, not just the school. In fact last year we ran the school mini-buses to various care homes to collect/drop off anyone who wanted to attend.
The summer fair is very much a family & friends event - not open to the general public.
So really we need to know - who gets the money from the £7 chutney?