"They both make a ton of money but they also spend a ton. And they are sparing no expense with their new house," a source tells PEOPLE in this week's issue. "$20,000 fixtures, the perfect flooring – the costs have been endless."
X17online; Inset: Getty
Meanwhile, the couple's Bel-Air mansion remains on the market.
For more from Kim and Kanye – including their separate finances, lavish home plans and what Kim thinks about her husband's Twitter drama – pick up this week's issue of PEOPLE, on newsstands Friday
Forbes estimates Kardashian's 2015 earnings at $53 million and his in 2014 at $20 million, but West turned heads when he tweeted he has $53 million in "personal debt" and publicly asked Mark Zuckerberg for $1 billion. West , 38, later clarified his remarks, tweeting that he is "personally rich" but needs "access to more money in order to bring more beautiful ideas to the world."