Advertisers are paying $250,000 to be in CNBC's sold-out Republican debate

The presidential debates have become big business for their network hosts.

CNBC has apparently sold out of its time during Wednesday's Republican presidential debates, reported THR.

The news network is charging $250,000 and upward for 30 seconds of advertising time during the program, titled "Your Money, Your Vote." That's five times CNBC's usual $50,000 rate for promo time. And it's 25% more than CNN charged during the Republican debate it hosted in September. To put the rate in perspective, NBC charged about $4.4 to $4.5 million for 30-second ads in this year's Super Bowl.

Clearly, these advertising rates are based on the network's expectation that it will do just as well or better than the debates have rated for other networks this year-which can probably be traced to Donald Trump's participation.

The GOP debates so far have brought in 24 million and 23 million viewers for Fox News in August and CNN in September, respectively. Even the Democratic debate earlier this month attracted 15.3 million viewers to CNN.

To date, CNBC's highest-rated debate was a Republican standoff in November 2011 that included Mitt Romney, Newt Gingrich, and Michele Bachmann, among others. It attracted 3.1 million viewers.

On Wednesday, CNBC anchors Carl Quintanilla, Becky Quick, and John Harwood will moderate the debate live from the University of Colorado Boulder. This time out, the candidates will debate issues surrounding the economy, such as unemployment, tax cuts, technology, and retirement.

Earlier this month, Donald Trump threatened CNBC that he would pull out of the debate if the network didn't keep it to two hours. The network ended up making the change.