I really enjoy this delivery driver anecdote!
I'm sorry to say, though, that I fail to see how it connects to what "greed" might mean...
I liked where you were going with the "trickery" angle. When I first read that, it made me think about how there's a spectrum of trickery that goes from "fair and expected in bargaining" (like hiding information. i.e. the highest price you'll pay) to "basically theft" (like passing off a forgery as legit).
So in the most extreme cases, trickery is theft. Where is the "greed" bit though? Is greed just the tendency to try and deceive people in order to get more out of them than they'd otherwise voluntarily trade if not for having been deceived by you?
I feel like colloquially, "greed" has tended to mean "wants to get a lot for himself and not share with others". Which is a pretty questionable definition in the context of a free market...