There's one thing that came to mind after watching that episode.

"good thing trading with my friends never got that complicated."

thence r I trade I keep these rules in mind.

1, bring only what you are trading.

2, let the person your trading with have what they want.

3, when selecting from the trade persons goods always ask if your selection is excepable.

4, the goods exchanged should be of equal amount.

5, both participants should feel the trade was fair.