Levi Johnston is shopping a tell-all memoir about his experience with the Palin family, the National Enquirer reports. Insiders say the estranged father of Sarah Palin’s grandson is hoping to start a war chest in advance of an anticipated custody battle. “If Levi could get a million bucks, it would be worth telling all he really knows,” a source said. “He knows what really happened inside the Palin family.” (More literature stories.)