How much was the shake in Pulp Fiction?

Pulp Fiction is one of those movies where nearly every scene is a classic that features at least one quote that has become culturally significant.

Seriously, see if you ever happen to catch it playing on TV and try to only watch a few minutes. Like an episode of Seinfeld, something perks up in your brain and you say to yourself, "Oh yeah, I love this scene! I'll turn it off after this one."

Next thing you know, you're starting it over for the third time in a row.

And the scene where Vincent Vega and Mia Wallace visit Jack Rabbit Slim's is one such scene that will suck you right the hell in for the night. In said scene, Mia orders a milkshake — which seems like a pretty normal thing to do, but the price of it really blows Vincent's mind. How much is it?