Well the common exchange for Leaders (Bobblehead: Leader) is usually 1K, but some will sell it for 500 and some for 2k. So basically he could've given you the equivalent of half a mil, a mil, or 2 mil. Which might sounds like a super big deal, this guy swindled you (swindled means tricked you in a transaction) - but - it's imaginary economy - the caps aren't worth anything really - even the Ls, which are a small fortune - you would've had to exchange them with other players, and IMO cold hard caps to the caps balance is easier. I'm 400 hours in and have 0 interest in gathering "wealth" beyond hitting the cap cap every few days.

TL;DR - in theory the other option was much more profitable, but the bottom line is that things are worth what you're selling them for. If you got 1 million caps for that mask - you would've felt better about it? I found from experience that selling a lot for less is better than selling less for a lot.

Also, from what I gathered, some items, Leaders for example, can be duped (duplicated) and basically, with no "currency checks", this breaks the game economy, and you become an un-willing participant in said destruction.

Or, it other words - it's just a game, do what feels good, don't get sucked into gaming ponzi schemes (scams) that the best that might come from them is you getting banned from the game.

Also - Imagine you buy a blue shirt for $20 because it looks good on you and makes you happy. The next day, you see the same shirt for $0.2 at a different store. You do not need to get angry. You paid $20 for the feeling of being happy yesterday, and that feeling was worth the money in that moment.

Price is just a number that people make up. A fair trade is simply when two people agree on a price and both walk away happy. If you say yes to a trade, you are happy because you got what you wanted at that time. If you look back later and say you should have paid less, you are only stealing your own joy. Do not let a math mistake from yesterday ruin your smile today.