Britney on a Budget

After years of spending her millions on vacations and dead-of-night shopping sprees, Britney Spears has been put on a tight budget by a team of advisers.

"Britney was never worth nearly as much as many thought she was," a source close to the pop diva tells OK! exclusively. "Those figures of $100 million or more were so off the mark."

In fact, the best estimate for her net worth is $40 million. Brit's team wants to preserve her fortune so she is comfortable and can support her kids, Sean Preston and Jayden James, even without any additional income.

The source says, "There's going to be some serious belt-tightening." The estimated $100,000 a month she'd spend on entertainment and vacations may be cut to 10% of that, and her $16,000-a-month clothing allowance will get halved. OK! has learned that as of April 1, she will let go of her $30,000-a-month Malibu pad that she hasn't visited in months.

Brit's dad, Jamie Spears, cut off her credit cards when he became her conservator. He and attorney Andrew Wallet are in charge of her estate. Her brother, Bryan, and another attorney manage the fund that administers her daily spending.

Now, the main financial drain is legal fees, round-the-clock security and medical costs. "It's taken a huge team to bring some normalcy out of the chaos that existed," the source says. "This team will have to be in place for years." The medical team alone usually has seven doctors and therapists. The legal team handles her finances, custody of her kids and the restraining order against Sam Lutfi. "Her legal bills alone could top $1 million this year," another insider familiar with the situation tells OK!.