Given the very shallow depth of the market, a prospective bidder who intends to create the illusion of a low market price can easily depress it by selling just a few hundred coins at strategic moments. From a Game Theoretic point of view, it makes sense for all prospective bidders to act independently to artificially keep the price low so that all the other prospective bidders wouldn't bid the price up too high for the big 50K coin prize.

On the other hand, they don't want to push the market down too low because then some other prospective bidder will just buy them out at the lower price.