Regardless of how awesome we do there will always be a few jerks that want to poo poo your achievements, I think that is how they make themselves feel better.
You made an amazing profit and created a win-win scenario, which I highly respect. You made a great profit, and the person that purchased it from you will probably also make a great profit, or add to an already awesome collection :-)
If I purchased something for $20 and then flipped it for $5,555, I would be the hero of the reseller community lol
People will always say you sold to early or too late, but I am sure that 99% of people would have done the same. As long as you are happy with your decision, that is all that matters, and I am extremely happy with my decision to sell when I did.