Historic Traders have a great deal of experience in working on a great variety of events, and realise that organisers need to generate income not just to cover the costs, but also to make a profit. However, obviously none of us like this to be at our expense, as we have also invested considerable money and time in our presentation.
In general most traders will be reluctant to pay more that £20 per day in advance unless they are absolutely certain that the event is going to be a major commercial success.
One way of paying a site fee is to agree to a percentage tithe of profit. Please note that this must be a percentage of profit, not of take. If you consider that all prices have to include VAT, once that and the traders travel expenses have been deducted, asking (say) 10% of take is financially impossible as the total deductions would then amount to about 40% of the price of each item. Which would leave the trader with less than the item cost to produce in the first place.
Also, some traders specialise in selling a few high value hand crafted items. Their daily “take” may be quite high, but they will make less profit per hour’s work than a trader who simply buys wholesale and sells on. Another problem arising from a tithe is that in effect it means that the traders have to reveal their income to the organiser. Not all traders are prepared to do this!
Catering and refreshment traders all know their criteria and profit margins. They will almost certainly also have to provide expensive refrigeration units etc in order to comply with food hygiene regulations etc, and need to be negotiated with individually. With a major caterer this negotiation will almost certainly involve the question of sole trading rights, and a written contract.