Quoted from ralphs007:
Greedy people look at the world as a zero-sum game. Instead of thinking that everyone would benefit as the pie gets larger, they view the pie as a constant and want to have the biggest part. They truly believe that they deserve more, even if it comes at someone else's expense.
Just sold a Medieval madness that i swapped for my GnR 63 days before. I listed it at 2k under what i could have got, as that was what GnR was listed for, the swap was one of those both happy deals and i wanted to pass the happiness on in this case.
It sold in under 2 mins with no haggling and six people queuing up for it.
Not saying i always do that as when i sell at a profit, it's knowing that the next machine i want to buy will be more than it was when i bought the one i sold.
But in this case i didn't have it long enough for a profit to seem reasonable.