Wordplay had a very quirky scoring system, as I recall. The connecting dollar values for correct guesses, if applicable, was a different way to build one's score, but not knowing what the hidden values were before the reveal seemed like a crap shoot, especially in the later rounds. They should have had a standard money amount for each of the 3 rounds (i.e. first round values are $100, second round $200, third round $300).
If tied after the 3rd round, Tom could give a toss-up double definition and the first to buzz-in correctly wins the game, with each player keeping their winnings.
It didn't seem like the dollar values for each word were based on a word's difficulty level, either.