Spend the weekend at Princess Diana's family estate

The brother of Princess Diana is allowing the public to spend a weekend at the noble family's ancestral seat at Althorp in Northamptonshire, located about 60 miles northwest of London.

Though the estate has been open to visitors since her 1997 death, this marks the first time that outsiders have been permitted to stay overnight at Althorp. Visitors will even be able to stay in Diana's old bedroom.

Christened "Heir BNB" by NBC News, the venture is a fundraiser benefiting the Whole Child organization, which is devoted to improving conditions for orphans. The charity was founded by his American wife, Countess Karen Spencer.

But it will cost wannabe aristocrats dearly: Prices start at $25,000 for a private bedroom or $40,000 for a premium bedroom. Truly big spenders can bring a party of 18 for $250,000.

If that's too rich for your blood, you still have a chance. Weekend stays will also be awarded to the top two fundraisers who either bring in the most money or get the largest number of individual donations. And for the more creative types, you can write a 500-word essay or shoot a 90-second video about how you've helped others to "embrace their future," in keeping with Whole Child's motto.

The Spencers gave NBC News' Cynthia McFadden an intimate tour of the 500-year-old mansion and grounds, including parts of the estate that have never been seen by the public. It airs  Sunday 7 ET/PT on the Dateline spinoff On Assignment. Viewers can catch a preview Friday on Today.

"I've always thought of this house as contributing,” Earl Charles Spencer told McFadden. “It's not just a little bastion or fortress of privilege."