An expensive beer

A monkey enters a bar and orders  a beer. The waiter is very surprised, but then he gives it to the monkey.

The monkey drinks the beer and then asks for payment. The waiter is more surprised and says:

“100 dollars .”

The monkey pulls out 100 dollars from his pocket and pays. The waiter is stupefied:

“Excuse me, but it’s the first time I see a monkey at the bar !”

The monkey answers angry: “It’s no wonder with such prices !”