We went to Whipsnade a couple of weeks ago with our daughter and grandson. Admission was £103.
When my kids were young my Mother paid for us to have a season ticket, no way we could afford it. Kids in car, packed meal to avoid expense, and stay all day for the price of a couple of gallons of diesel
As I worked in London I had a season ticket to Euston. A perk of that was taking the kids from Milton Keynes to London for a quid each, full travelcard including tube and buses. Walk around the sights at no cost. Science Museum and Natural History Museum were free. Ditto British Museum.
Kids still mention how much they enjoyed those trips and how much they learned.
I don't grudge our poorest kids having a few opportunities to see and do things they'd never get near if parents had to bear the full cost.