It's not a conspiracy.
What would two sellers have to gain from such a transaction? Nothing. The only way it could POSSIBLY be a conspiracy is if billmarioman bid on the original auction to raise the price, accidentally won the item, and then re-sold it to avoid the appearance of collusion. There is never any (mutual) benefit for one guy to buy an item from another and then re-sell it. The original seller may as well just sell it at the re-sell price, if that's what's going down.
But that's clearly not what happened. Billmarioman sniped the original auction and got it at the minimum price. There's no "gain" for the original seller. So it's just coincidence that they live in the same town.
As for billmarioman's greed... yeah, it may look greedy to buy it for 100 and then re-sell it for 200. Hell, it IS greedy. But consider this: people had TEN DAYS to bid on the $100 auction, and they didn't. No one else even bid on it. Billmarioman gave people their chance, and they all passed it up. So if he wants to try and sell it for 200, more power to him.
Of course, since no one was willing to bid 100, I doubt he'll get any takers at double price...