EXCLUSIVE: Jessica Simpson's Spending Sprees — Newly-Single Star is Ponying Up Big Bucks for High-Price Solo Pampering

Jessica Simpson is one of Hollywood's biggest spenders, treating herself to the very best of everything, RadarOnline.com can reveal.

"The mind boggles at how much money Jessica spends every year," an insider of the singer turned designer, who's made more than $1billion from her fashion line and music projects.

It's been reported the 45-year-old has a hairstyling team on call that costs $230,000 a year, and that she forks over $1,000 a week on eyelash-extension touch-ups and another grand on tanning – though she denies spending that much.

The Dukes of Hazzard star's "Graceland-like" estate in Hidden Hills, Calif., is fitted with every possible five-star amenity, including tons of guest rooms and office and recording facilities, the source said.

Another perk of being a billionaire: getting house calls! "I don't think Jessica has been to a doctor's office in 10 years," dished the source.

But unlike many uber-rich people, Simpson's greatest joy is spreading the wealth. She's even generous to estranged husband Eric Johnson, the father of her three children, Maxwell, 13, Ace, 12, and Birdie, 7. "She totally underwrites his life, even though they don't live as husband and wife anymore," the source shared.

Simpson's new boyfriend, Nashville-based musician Thomas Eisenhood, is also said to benefit from his relationship with the star.

"She loves supporting the people closest to her, and she doesn't mind having a couple dozen people on the payroll," the insider said. "She's actually proud that she can give these people great lives and overpay them while she's at it."

She goes really overboard at the holidays, the source explained, giving her staff lavish gifts and hosting catered dinners.

"It's clearly exactly what makes her happy," said the insider.