9. Sell Fusion Cores For Full Price No Matter The Charge
Fusion Cores are the keys to getting your Power Armor moving and - surprisingly - one of the first things you'll do in the game is use one to hop into an armoured suit to battle a raging Deathclaw. However, they don't last forever, and before you know it all that running around and avoiding fall-damage by landing like the Hulk will whittle your core down to zero. Before that happens and it becomes useless though, hop back out your Armour and remove it. See, many merchants - not all, but many - can't tell the difference between a fully-powered core and a depleted one, so it's far more beneficial to trade yours in when it's about to break anyway. This works for the various near-depleted cores you'll find around the Commonwealth too, so snap them up regardless and peddle to barter-happy traders.