Shayari Bazar

A man goes into a barber shop and gets a haircut for $15. He pays the barber with a $20 bill, but the barber doesn’t have change. The barber goes to the neighboring flower shop and trades the $20 bill for a $10 dollar bill and two $5 bills. Then he gives the man his $5 in change. Later the lady from the flower shop confronts the barber and tells him that the $20 bill he gave her was counterfeit money. The barber agrees and he gives the lady a different $20 bill. Later that day he tries to figure out how much money he lost. How much money did the barber lose?