A 2013 Japanese puzzle called "Dollar puzzle"

A 2013 Japanese puzzle called "Dollar puzzle" was launched in one
Canadian universities and only 30% of students have been able to answer it correctly,
After this puzzle was considered a measure to determine the IQ of each of the answers, so it was
Consider anyone who has been able to answer correctly that their IQ is
The IQ 120 is often higher than the overall limit.
At first the puzzle may seem simple but it may take minutes and hours to answer it
Correctly, it needs to focus intensely and put probabilities:

Puzzle :

There is a quorum for a bookstore to buy a book worth $ 10
With a paper of the category of "$ 100"
But they are fake and unreal,
He gave the "$ 100" counterfeit to the owner of the shop and did not notice the shop owner that it was forged ..
So his owner took it
The shop was unable to disassemble it "That was not with him the disbursement of smaller categories"
He went out to the owner of the restaurant next to him to give it to him for smaller groups ..
The shop owner gave the book and
The rest of the $ 100 ($ 90)
To the person who took the quorum and left.
Half an hour later, the restaurant owner came to the bookshop owner to refund him $ 100.
And tells him that it is forged .. The shop owner took it without saying a word because that was his fault, because he hasn't check if it was real .. And gave the restaurant owner another $ 100 really.

the question :

How much did the man who owned the books shop lose?