Sorry matt, I don't take kindly when people assume they know what I would do. Your statement is completely false, I do not believe that everyone would do as you say. Some perhaps but definitely not all, I being one of them.
A business has no moral values...of course not...but people should and many do.
Frankly speaking if it were my friend I would have helped them sell it to maximize the amount of money gained, especially given the circumstances as described and being called upon as knowledgeable by my friend. However, I was not there and I don't know the conversation that transpired and I don't know the the financial status of the individual with the watch. For all I know he was independently wealthy and didn't give a rats a$$ about how much he got for it. If that is the case then kudos to the OP for scoring a great deal. If not then I don't know. All I can say is that the way the OP came across was a bit of a brag on how great a deal was scored at the expense of a friend in troubled times.
Now back to your regularly scheduled program