Eyes As Big As Saucers

I rang up a man whose total was about $8.50. After the transaction was completed, his (10-year-old?) son came up and asked him how much it came to.

I replied, "A hundred and five."

You know the expression, "eyes as big as saucers"? Seriously, they were!

After a couple of seconds, he turned to his dad and said, "How much did it really cost?"