"Would you pay extra for the water park" at the end of a fun day is a proxy for "did you appreciate/receive value from this thing you just finished enjoying?"

"Would you pay extra for the water park" at the end of a fun day is a proxy for "did you appreciate/receive value from this thing you just finished enjoying?" Whereas, on a random Tuesday, announcing: "Want to come to the water park? PAY US MORE MONEY." Is a proxy for "we're taking something away from your admission ticket and trying to backdoor a new charge".