An idea for Joker:
Played for three prizes like Rat Race, two medium range prizes and a car. The pricing part involves three small prizes.
Eight cards on are the board, four pairs, two Queens, two Kings, two Aces and two Jokers. Each card has one digit on it's backside, and each non-Joker pair is associated with the price of one of the small prizes. So, for example, if one of the small prizes was $26, card #2 and card #6 would be the pair of Queens. The two Jokers would have numbers not found in any price.
The contestant picks cards one at time, trying to find the three pairs. Each pair the contestant finds earns them a big prize, first pair gets them the first prize, second pair gets the second prize, and all three pairs gets them the car. However, if they pair up both Jokers, they lose everything. They can quit and take what they've won if they don't want to risk losing it.