As talk of a big Britney Spears Las Vegas residency deal at Planet Hollywood continues, two Vegas show producers say they wouldn't necessarily put up the reported $100 million that's been tossed about as Brit's compensation...because she's far from a sure thing in terms of drawing power.

Speaking to the Las Vegas Review-Journal, Adam Steck, the producer of five current Vegas shows says, "My gut tells me she doesn't have the goods to deliver on a consistent basis."

In addition, Joey Battig, a producer who tried to sign Whitney Houston to a Planet Hollywood deal in 2009, tells the paper, "You're rolling the dice. This is not Celine Dion."

Battig says that the rumor is that Britney wants $450,000 per night to perform, but he say's, "I wouldn't guarantee her more than $150,000 a night, but I'd say, 'Roll the dice with me on the back end. We were guaranteeing Whitney $450,000 a night, three nights a week for a year. That's $1.3 million a week, $43 million a year."

According to Bettig, the only way Britney could earn back a yearly salary of $100 million for a producer would be to do five shows a week for 32 weeks a year, at an average ticket price of $150.

He describes such a deal as "a crap shoot," adding that whoever produces it "has his head on the chopping block every night."  As Bettig explains, "If someone doesn't show up, you can give the refunds back, but you can't recoup those numbers...I wouldn't take that risk."