Big Bucks! Caitlyn Jenner's Pricey Payday For Her Memoir Has Publisher Worried

Caitlyn Jenner got a $4 million book advance for her upcoming memoir, but now her publisher is regretting it, RadarOnline.com has exclusively learned.

As RadarOnline.com reported, the 67-year-old will release The Secrets of my Life in April. But after a world-wide media blitz, are there REALLY any secrets left?

"Caitlyn has already told so much of her story in an ABC primetime special with Diane Sawyer and on her own E! reality show that there isn't that much to tell," sources tell RadarOnline.com.

Last month, Jenner revealed the cover of her book, and released a minute-long teaser video

"After a lifetime of secrets, and a long personal struggle, Caitlyn Jenner is finally learning to live as her true self," the clip teased.

The book is expected to address her life as an Olympian, a father, a husband, and then coming out as transgender back in 2015. But the publisher is secretly worried that Jenner has spilled too much already.

"When the deal was signed there was still so much that we didn't know about her and Bruce Jenner's past," the sources said. "That isn't true anymore."

And there is serious concern that they overpaid for the rights to her story.

"The publishers are really worried about this book. Everyone in the industry thinks they paid way too much," sources admitted.

One competitor tells RadarOnline.com that they were bidding on the memoir but dropped out at $1.2 million.