LED LIGHTING CHINA

Someone  took a hundred dollars cash to a shop and bought  some product with 25 dollars, because the owner did not have change. and then the owner use this money to small vendor  for changing  100 dollars into coins, and then returned to the 75 dollars to that person. that person took 25 dollars product  and 75 dollars  away. A little while later, small vendor find the owner next door, and just said that 100 dollars is  counterfeit currency. Owner of a detailed look, it really was counterfeit. Really owner had to give 100 real dollars  to small vendors.
Question : In the whole process, what 's the total number of losses on money for owner?
(Additional requirements : 25 dollars product  by the owner of only  20% of the profits)