Mariah Carey's appearance on 'X Factor,' which has been rumored for months ever since she was under consideration as a potential judge, is apparently not happening. Why, you ask? The diva wanted $300,000 for a performance of 'All I Want for Christmas Is You' with Justin Bieber.

Showbiz 411 says Carey was set to duet with the teen star on an episode of 'X Factor,' but her requests for backup singers, dancers, makeup and a band would have cost around $300K. Even huge Mariah supporter Simon Cowell couldn't get on board with those demands.

A source tried to justify the requests by telling the website, "Mariah hasn’t performed live in about a year. She wanted to make sure everything was perfect. She certainly doesn’t sing to a track."

The drama surrounding Carey's possible appearance on 'X Factor' started earlier this year when Cowell revealed that she would not be a judge but declared, "We have to find a role for her." Cowell then all but guaranteed she would appear on the show at some point, even though her pregnancy was making it difficult to schedule. Finally, just as her role was finalized, Hurricane Irene caused her to miss the important shoot.

Even though Mariah and 'X Factor' couldn't get together this time around, don't count her out for next season's premiere. By then, she should have brand-new music to promote.