Honesty Hour: A friend of yours has a desire to sell their old Pokémon cards and would be willing to give them to you for $30, you can see that there are some very valuable cards (worth around $500 in total) in their collection... what do you do?
Buy them for 30, sell them for 500 and then give $100 to my friend saying that they had a rare card and I couldn't keep the money to myself. Total profit: 370 dollars and a happy friend