Would You Bid Against Your Friend On A Ebay Item?

"If it is a sought after coin you will always have a large sniper bid at the end (usually as much as twice its value to guarantee they get it). Unless you are the one doing the snipping you wouldn't be able to form any strategy to keep others out."

unless of course your strategy was to place a huge bid ahead of time, in order to prevent losing the coin to a sniper. On the other hand, this strategy could be costly to either winning party.