I went up to the McMichael Collection recently. (Its history of ownership and control is unique in Canada, I think; see the Wikipedia article for more.) The sign at the entrance desk says an adult ticket is $20. I handed over a $20 bill.
“Twenty fifty,” said the attendant. I was a bit confused, but handed over a fiver and got change back.
My receipt said admission is $17.70, plus $2.30 HST (harmonized sales tax of 13%; in Ontario that is the combination of 5% federal tax and 8% provincial tax). That equals $20. A nice round number.
But then the receipt says: “Processing fee: $0.50.”
I emailed the gallery: “Why is the fee charged on cash payments?”
The response: “The Software Processing fee applies per ticket transactions including cash.”