Not as in celebrities, but for hosts that could skew the game...
How much leeway did Jim Perry have in dealing with Instant Bargains on "$ale Of The Century"? I know he'd cut prices down (and he always loved a three-way tie) and he'd also throw out some $100 bills to entice the player, but was there a limit on how far he could go to avoid unduly influencing the game?
With Jim Perry and Tony Barber, I never saw either lower a bargain price by more than $5 on too many occasions- only when the game was close. I think they had a bit more leeway later in a champion's run if it would make the games more exciting. I remember a few games when the champ was going for the lot where Jim or Tony would offer the contestant a couple thousand dollars- Tony pulled that mnore than Jim did, IIRC. I wouldn't be surprised if there was someone offstage who let Jim get to a certain point, then gave him the sign when he had to close the bargain.
Staying on $ale, and on topic, we normally don't see contestants skew the game, but I remember on Temptation there was some woman who didn't like one of the male contestants. She was pretty far back by Fast Money, and her sworn enemy was down a question or two. She immediately buzzed on every question and screwed him out of the game. She even referenced her dislike in her post game comments. IIRC, he didn't get asked back. Fair or foul?