Yes, I think there is some aspect that's supposed to be about a trade that has some effect outside the game. I think these are generally not desirable in games

Yes, I think there is some aspect that's supposed to be about a trade that has some effect outside the game. I think these are generally not desirable in games because they either reward those who have more resources outside the game or they reward those for which the game represents a larger fraction of their life as a whole, and this is generally against the usual fairness we tend to prefer in games (especially a bias towards this already exists through factors which are hard to control. Explicitly making it part of the game is already unnecessary).