$20.00 CAD. It's a Canadian term derived from the apparent price of a large jar of Cheez Whiz
in the Canadian territory of Nunavut. The price was jacked up so high because of how expensive it was for Kraft to export their products to Nunavut.
Somehow, the term eventually reached southern Canada, and Canadians found it humorous how much Cheez Whiz costs up north, so much so that they started using it as a synonym for $20, even after the price of Cheez Whiz went back down. People commonly put the blame on certain documentaries made around the time about the standard of living in Nunavut, many of which commented on the price of Cheez Whiz.
Its proper name would actually be a Nunavummiuq Cheez Whiz, as that's the proper demonym for Nunavut, but people are either too lazy or too stupid to figure out how that word is pronounced, so in common speech it's just referred to as a "Cheez Whiz," leaving in the dark everybody who is unaware of this obscure slang.
"Dude, be careful with that, it's gotta be worth at least one hundred Canadian Cheez Whiz."
"That comes to 2 Nunavummiuq Cheez Whiz, eh?"