Hi AC,
You'll notice in that particular tournament that only 28 players finished with a score that wasn't a withdraw. When a tournament cannot pay out all of the designated places (in a Ready-Go's case, 30 people) the remainder of the pot is redistributed to players who finished using the same percentages that were paid out initially.
So basically, the winner of that tournament got the usual 13.75% as a payout which is normally $5.50. However, since only 28 players posted there were credits left over after the initial round of payouts. All tournament purses must be paid in full, so an additional 13.75% of the purse's remainder was given to the player in 1st, 10% of the remainder was given to 2nd and so on down the list until there were no credits left in the purse.