depends on whether he was able to rid himself of the fake $500 by giving it to someone else!
Logically though:
KOC's friend has given change of $180
He is also down one box of balls $250
and the profit on the balls $70
Finally he is down the $500 he had to replace.
That brings a grand total of $1000!
Ouch!
A fake $500 turned into $1000 lost?
__________________
If you cannot take the shoulder down the clubshaft plane, you must take along some other path and add compensations - now, instead of one motion to remember, you wind up with at least two!