About 6 months ago, I was selling a camera lens on Facebook Marketplace. I initially listed it for $50, and no takers after a week. After lowering the price to $40, after several days, I had over 20 people reach out. The first guy who did seemed nice, and we agreed at $40. One of the people who reached out later offered $45. I came back to the first guy and asked him if he was willing to pay $45 for it. He begrudgingly agreed, but then later changed his mind and called me "rude and immature for going back on my word, and he hoped one day when I'm older I would honor my agreements." I ended up selling to the guy who offered $45.

For context, I am 23 and the guy, at least according to his profile pic, looked well over 50, maybe 60. I've been conflicted about this and not sure if I made the right move. I gave him the opportunity to match the offer, but he called me out for dishonoring our agreement.