Based on the ratings home run NBC scored last December with its live presentation of “The Sound of Music,” it wants marketers to pony up at least as much money for its “Peter Pan Live” as they spend for a 30-second commercial on the CBS hit “The Big Bang Theory.”

NBC “is seeking between $350,000 and $400,000 for a 30-second ad in the show,” writes Brian Steinberg, who covers TV advertising for Variety.

At the bottom of that range it’s a little more money than CBS is charging for a 30-second spot this season on the uber-popular sitcom “The Big Bang Theory,” according to Advertising Age’s annual survey of ad prices for prime-time shows.

While “Peter Pan” is, historically, fine family fare, a number of buyers wonder whether it will get as large a tune-in as “The Sound of Music,” which had built-in star appeal with Carrie Underwood. The lead role in “Peter Pan” will be played by Allison Williams, who is not a household name.

Writes Steinberg, “By many views, ‘Peter Pan’ is expected to perform well for NBC. It will air on Thursday, December 4, a time in the programming cycle when many networks air fewer originals and put some dramas and comedies on a short holiday hiatus. But there is a sense among media-buying executives that it may not perform as well as ‘The Sound of Music,’ which notched 18.5 million live viewers and nearly 22 million who watched it either live or up to a week after its debut on December 5, 2013.

“ ‘I am sure NBC will put heavy promotion behind it and I think it will definitely be a win for them … just not an 18 million-viewer win,’ said Billie Gold, vice president and director of buying and programming research at ad-buying firm Carat. Audiences will not be as familiar with Allison Williams, she said, as they were with Carrie Underwood.”

Allison Williams, left, as Peter Pan and Christopher Walken as Captain Hook in a picture recently Tweeted by the show’s executive producer Neil Meron