Como se fala sobre dinheiro em em Inglês - vocabulário

 Here are some basic examples:

• $1 – a dollar or one dollar.
• $3 – three dollars. *not three dollar
• $50 – fifty dollars. *not fifty dollar

Numa conversa informal, normalmente se o usa o termo  buck para se referir ao dolar americano. 

• $1 – a buck.  or one buck 
• $3 – three bucks.
• $50 – fifty bucks.

Quanto houver também centavos, pode-se falar de duas maneiras: 

#1 – Forma longa:

• $1.33 – one dollar and thirty-three cents.
• $13.79 – thirteen dollars and seventy-nine cents.
• $110. 99 – one hundred ten dollars and ninety-nine cents.

 #2 – Forma abreviada:

• $1.33 – one thirty-three.
• $13.79 – thirteen seventy-nine.
• $110. 99 – one ten ninety-nine.

http://www.myhappyenglish.com/free-english-lesson/2013/04/22/english-pronunciation-of-money-lesson-how-to-pronounce-dollar-amounts/