Originally Posted by dehash

Some places don't keep more than 50$ in cash in register at any time(I see this signs very often).
Once I received counterfeited 100$ bill. It was bleached out 5$ bill with 100$ picture typed on it. If you try counterfeit pen - it shows yellow line. But surface was kinda suspicious. Only if you check water signs you can see the difference.

Very often I see small business don't take AX(4% fee), or gas station with prices lower for cash paying customers vs credit card.