The answer to this question isn't really a cut and dry, black and white answer, and in trying to be understanding to both sides of this story, I sort of empathize with both parties. Right off the bat though, I will have to admit that I do sort of agree with the disgruntled guy about opening their mouth and 'ruining' a potential score for someone else, but at the same time I'd like someone to do that for me if I was the seller, so it goes both ways here. If I'd like someone to let me know if I have something valuable, I can't really complain if someone more knowledgeable informs a seller of the same thing about an item I want. It's a double standard, and you can't have your cake and eat it too, and then act like a spoiled little turd. One thing is for sure though, that guy's behavior and the way he conducted himself in his emails is absolutely unacceptable, and there's no excuse for that type of behavior. He's giving you a hard time for informing someone else about what they have simply because he wanted to profit from it. His reasoning has nothing to do with ethics or being a better person, he's just a greedy s.o.b. who was beat at his own game!
I once was in the market for a bass guitar. I saw an ad on Craigslist, met with the guy and bought the bass and an amp from him. I have no idea the year of the bass, and it was gross. It reeked of cigars and had grime and corrosion all over it. He said he used to play it in bar bands back in the 80's and hasn't played in years. I took the bass home, took it apart, dated the pots, the neck and serial number. It all came back 100% original to late '75 early '76, and cleaned up to where it looked practically new and is now worth about $1,800. I sold the bass amp that it came with for $60. I was told by people that I was dishonest and should have gone back and told the previous owner, and returned the bass after I discovered it's value. I disagree because the guy was savvy enough with a computer to post an ad on Craigslist, he could have easily typed the serial number into google or taken 5 minutes to look on ebay to see what they are worth, but for whatever reason he did not. That's his fault, not mine.
Today there are so many tools at our disposal that make it so much easier for people to research and find out what things are worth, and for the most part it takes relatively little effort and time. Most people do not want to put in the effort or time to do the research because they are lazy, and I have no sympathy for those people, and if they sell an item for a lot less than it's worth because of laziness, then you can't blame the buyer, you blame the seller.
I think every situation is different. If I was at a garage sale and a little old lady had a vintage uke for sale for like $10 I think I'd be compelled to tell her it's real value. If it was a younger person who is most likely savvy with a computer, I'd be inclined not to, and take advantage of the situation. I know this probably is not morally correct, but I'm just being honest, and I'd dare say that this may be the way a lot of us would approach a situation like this, but are afraid to admit it.
I once was in the market for a bass guitar. I saw an ad on Craigslist, met with the guy and bought the bass and an amp from him. I have no idea the year of the bass, and it was gross. It reeked of cigars and had grime and corrosion all over it. He said he used to play it in bar bands back in the 80's and hasn't played in years. I took the bass home, took it apart, dated the pots, the neck and serial number. It all came back 100% original to late '75 early '76, and cleaned up to where it looked practically new and is now worth about $1,800. I sold the bass amp that it came with for $60. I was told by people that I was dishonest and should have gone back and told the previous owner, and returned the bass after I discovered it's value. I disagree because the guy was savvy enough with a computer to post an ad on Craigslist, he could have easily typed the serial number into google or taken 5 minutes to look on ebay to see what they are worth, but for whatever reason he did not. That's his fault, not mine.
Today there are so many tools at our disposal that make it so much easier for people to research and find out what things are worth, and for the most part it takes relatively little effort and time. Most people do not want to put in the effort or time to do the research because they are lazy, and I have no sympathy for those people, and if they sell an item for a lot less than it's worth because of laziness, then you can't blame the buyer, you blame the seller.
I think every situation is different. If I was at a garage sale and a little old lady had a vintage uke for sale for like $10 I think I'd be compelled to tell her it's real value. If it was a younger person who is most likely savvy with a computer, I'd be inclined not to, and take advantage of the situation. I know this probably is not morally correct, but I'm just being honest, and I'd dare say that this may be the way a lot of us would approach a situation like this, but are afraid to admit it.