I've been following the boards fairly frequently, and i keep seeing messages over and over and over about people using "buy it now" because the THOUGHT they won the treasure hunt. Then they get stuck as unpaying bidders, or they end up paying for items they never wanted in the first place.
http://pages.ebay.com/treasurehunt/howtoplay.html If you scroll to the bottom of that page, you will see an example of what the screen will look like when you ACTUALLY stumble across a treasure hunt winning auction.