Wow what a shit show...
FLIP A COIN ? At that suggestion I would have taken a dump in his front yard on the way out.
Alternatively this seller could have come up with some more creative methods to determine who wins such as :
Play each other in an entire game of Monopoly.
Each of you sleep with his wife - whichever she thought was better wins. (You both kinda either win or lose on this one)
Fight club.
From the sounds of it the other newbie is going to regret going to the coin toss unfortunately, you were trying to steer him right.