Because a stack of hundred dollar bills in my hand is very un satisfying . I have money what I want is to feel the cold metal of a lockdown bar in my palms of a my new favorite machine.
a lot of times when you have the sought after game the other machine will be brought to you ,so very little effort is required to get another game into the lineup.
If I sell and find the game I want, now I have to go get it and bring it home.
So perhaps Trading is a byproduct of Laziness ??
Sir Brian of Ortonville