Similar, I've just been to one of those events at a Stately/Posh Estate, where you have to pay an entrance fee just to shop. DH refuses to come with me as he cannot understand why anyone would pay to be allowed to shop. The entrance fee is £14.50 this year which in itself is plenty. It was busy full of middle class Home Counties pensioners.
Anyway my point, coffee, small paper cup, from a machine (not Nescafe and hot water), £5 or £9 for a speciallity coffee such as a cappucino.
Egg & Cress sandwich £7.50, Burger in a bap or a Pulled Pork bap were over £15. The baps looked like they were Costco, the burgers were alledgely 'posh' but looked small and dry. A single cookie £4.50.
I spent time looking at (and buying from) the speciallity craft stalls, which was the point of my visit, then left and picked up lunch from the local bakers along with fresh bread which was less than the £7.50 for the sandwich, baked in the county and fresh today.
We do a lot of city break type trips and do like to sit and have a coffee, but I need to see the price before I order. My drink of choice is a flat white and my target price is £5, I will pay more but over £8 and I am having second thoughts