Even celebrities who are past their prime charge a ton of money.

Speaking engagements, private performances or simple appearances can bring in hundreds of thousands of dollars.

Celebrity Talent International is an agency that represents huge stars like Adele, Elton John and Angelina Jolie, booking appearances for these stars and hundreds more.

Many of the appearance fees are listed on CTI's website and are shockingly high. Celebrities don't necessarily receive the full amount, but the fees are guidelines for what they expect.

Decades after 90210 made her famous, Shannen Doherty is still asking for a ton of money. Same for former musician/reality stars like Clay Aiken and Bret Michaels.

And you won't believe what the former Mr. Britney Spears charges.