Prince Harry, Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge stand on the balcony at Buckingham Palace in London, England. - 

A Royal baby could bring in a royal amount of money.

The Centre for Retail Research estimates that Royal baby fever could boost the British economy by nearly $400 million between July 1 and August 31. That includes supporters celebrating the birth (alcohol is expected to amount to $97 million), buying books and other media connected to the event, and sales from overseas well-wishers. The British royal family is offering baby products to mark the arrival of the newborn heir, which is due mid-July.

How will all that money get spent? Here's a breakdown, according to the Centre for Retail Research:

Festivities: $136 million
Souvenirs and toys: $125 million
Books, DVDs and Media: $119 million
TOTAL: $380 million

Given William and Kate's propensity to break with tradition, it wouldn't be surprising if the Royal couple didn't sell the first photo of their baby. But many other celebrity couples have earned big bucks selling off photos of their offspring.

Take a look at this chart, based on 2008 data from Forbes, of the highest-selling baby photos:

Of course, not every celebrity baby picture has been sold for millions to a magazine. Beyonce and Jay-Z first unveiled a picture of Blue Ivy on their websites, and the first look at Mariah Carey and Nick Cannon's twins came on an episode of ABC's "20/20."

Follow Daryl Paranada at @darylparanada