Just as the lyrics go in Kanye West's hit song "Gold Digger," he and his superstar fiancée, Kim Kardashian, have allegedly agreed to sign a prenupital agreement, TMZ reports.

The superstar couple will keep both of their assets separately before they tie the knot, as multiple sources have confirmed to the gossip site. Kardashian has an estimated net worth of $40 million, while Kanye West is purported to be worth $100 million, and while the couple are reportedly not worried about their relationship coming to an end, they have chosen to sign the agreement as a sound business decision.

The couple will also reportedly create a joint account of shared expenses, and one source even claims that Kardashian is worth more than West at the moment.

West proposed to his long-time girlfriend and baby mama at a meticulously planned evening event in San Francisco at AT&T Park featuring a 50-piece orchestra playing Kardashian's favorite song, "Young & Beautiful" by Lana Del Rey. The couple were joined by friends and family after West popped the question and Kardashian eagerly agreed, the jumbotron displaying the words, "Pleeease Marry Meee!!!"

Sister Khloe Kardashian posted a photo of the jumbotron to Instagram along with the caption, "Magical memories."

Fans expressed their excitement all over Twitter, and in regards to Kardashian's new 15-carat diamond engagement ring designed by Lorraine Schwartz.

"We believe this is an emerald or cushion cut," Mark Keeney of jewelry designer to the stars Ritani told Wetpaint Entertainment. "We peg this in the $4 to 5 million range."

"Kim's ring is D-flawless," a rep for Lorraine Schwartz told E! News. "It's the best color, clarity, and cut there is. There's no comparison!"

Not only is Kardashian's ring big and beautiful, it was picked out especially by West for being a non-conflict diamond with a totally ethical background, as the purchase of the ring specifically does not aid "rebel movements to finance wars against legitimate governments."

Kardashian's original ring (or so it is believed) from ex-husband Kris Humphries, which was recently auctioned off for $749,000 on Tuesday, Oct. 15 in New York by Christie's, much less than its original reported $2 million value, was also designed by Lorraine Schwartz.

The couple, who share a daughter together, North "Nori" West, are also not waiting to walk down the aisle, and plan to get married ASAP.