I've been to F1 races in the UK, Germany and Italy and the level of exploitation varied. For example, in the UK the circuit pays a fortune to FOM, which they barely recover through ticket sales so they then charge the concessions a small fortune which means a burger or an ice cream means you need a second mortgage.
Germany was better, although I think Hockenheim might have been as they got a special deal from FOM the year I went as the Nürburgring had reneged on their contract.
Italy was a disgrace. You paid €5 for a coffee, €15 for an inedible sandwich, and they confiscated power packs at the gate so you had to hire one off the "official" power pack supplier to keep your phone alive during the day.
How things will be in COTA I have no idea, but don't think you will get close to any of the drivers unless you have paid a king's ransom for special tickets, don't expect to be able to do a pit walk unless you have paid extra, and I suspect a programme will be about the same as your ticket.
Enjoy the weekend, but be prepared to pay, and pay, and pay.