This is ridiculous. I don't know how many of you watch the show, but the contestants this year are TERRIBLE. All of the fairly genuine contestants have been voted off in favor of the gossipy bunch who play "the game". Saying all that, this doesn't surprise me any. To be fair though, the producers have done this before...as a matter of fact, they did it LAST season (all the voted off contestants got to come back and compete in a full marathon for a guaranteed spot in the finale), and other similar twists have been added over the years. This is nothing different.
You sign the contract, and you're subjected to whatever rules, twists and whatnot they throw into the game. I'm with Matt. Kick em all off. Better yet, bring everyone back and only conduct the at-home prize for the contestants who had been eliminated.
This is one of the few reality shows on TV that actually offers a prize that ultimately beats the money- I wonder if they would have had the same problems if the grand prize (cash or merchandise) was under $50K.