(4) The first person to find each Hidden Listing, click "Buy It Now" and follow the instructions provided to successfully complete the mock purchase of the Hidden Listing will be the potential winner of the prize, pending verification of eligibility.
Because some of the people playing the game are not too bright. There is a sample pic of what a winning auction looks like on the "How to Play" link on the left side of the clues page. Pretty much any question can be answered in the links on the left side of that page.
Not referring to you...talking about those who actually bought stuff not intending to. The pic on the How to Play link looks nothing like the auctions people have complained about winning accidently. Yes, they do have to be buy it now.