I'm just guessing here...
But I know the dude had a private deal for the other cheek with a radio station. And I'm sure he thought they'd bid it up a lot higher to get the other.
That's an awfully cheap price to have such an ugly picture permanently etched on your body. I'd hate to be the poor bastard's proctologist and have to look at two assholes on one patient's body.
In fairness, he did reserve right of final approval in his auction. But if GonZo can get a conversation going with him it might yet be a done deal as I've seen the man sell air conditioners to eskimos.