"I call Todd on the cell phone [from the grocery checkout] and I say, 'Todd, you won't believe this cover!' And he says, 'Twenty million? Write me a check,' " Palin recounts. "He's good about laughing some of that stuff off."
The couple, who opened their home to Survivor creator Mark Burnett for a new adventure series debuting on TLC this Sunday night, spent two days talking to PEOPLE during extensive at-home interviews.
"Our whole life is under a microscope," Todd says, explaining the decision to do the series Sarah Palin's Alaska. "We wanted to showcase Alaska. It will be a positive thing."
For much more from the Palins – including the first look inside Todd's role in Palin's political work and how they are spending their new earnings – pick up the new issue of PEOPLE, on newsstands Friday