At Bromyard you can see all sorts of tickets displayed in the unorganised sessions in the town.
At Sidmouth we have camped opposite the the Caravan Park (Golf Club) in a bigger field that is flat & cheaper and relatively quiet. The bus comes by morning and evening & late, it is 1 hour's pleasant walk but not recommended in the dark.
I am not sure buying a ticket for the events we go to is cost effective, but it gives a measure of freedom of choice. But if the venue is oversubscribed the ticket doesn't give much priority, only queuing early will do that.
The rugby club is a good camping site for motor caravans, but not caravans, they don't allow even a 9 footer! People who have booked have got on with a large enough caravan (pick your excuse).

There is enough fringe at Sidmouth - though you can tire of them in the week without the free ceilidhs in the Anchor Gardens.

There is always the Connaught Tea Rooms - their portion control could be a problem if you are on a diet. But highly recommended. There is enough time in a week to do it all.