He lost a DVD -$14
Counterfeit $100 -$100
Gave $81 change -$81
-$195
If the store owner starts the day with $500 in the till, gets the fake $100,changes it with the other owner,puts that $100 in his till, he then has $600. $95 walks out the door with the thief, till is at $519, $100 goes back to other store, till at $419, started at $500. He's out $81 and the DVD.
$95