It makes me sad to think people are blaming the original seller for potentially believing someone needed something. You're technically correct that a dresser is not a need, but if I meet someone saying they're a single mother escaping an abusive relationship and just trying to help their kid regain a sense of normalcy by at least having a place to put their clothes that isn't the floor, I want to be able to give them the benefit of the doubt without people blaming me for being gullible because a dresser is not a "need".

I moved a long time ago and was getting some stuff of Craigslist just to get settled. I bought a table off someone who offered to give me a discount once I arrived. I think they saw me in shabby clothes and my old car and thought I could really benefit from the kindness. In reality I was doing well enough and it seemed like they could probably use the extra cash more than me. I told them I was happy to pay full price since it was extremely fair and they accepted. I really love that story because it's just two people recognizing that somebody may need something more than them and being willing to provide it. Restores my faith in humanity. It would suck to have the takeaway be that they almost got scammed out of some money because they had compassion for someone that actually didn't need it.

Edit: apparently I missed the part about wanting half the profit. I think it's ok to reach out to someone and let them know you didn't appreciate their behavior and another to do some weird guilting or fake extortion thing. Originally I was assuming some kind of discount was offered due to the reseller acting like they were in a tight spot, but with the original seller asking for more money I'm now questioning that. If the reseller bought it at asking price and didn't give a sob story to get a discount then there's really nothing the seller should be mad about. If the reseller lied that's a problem.