Some venture to say that the interview with Fox News actually cost the taxpayers money, as it was during work hours where the Representative is on the clock. In addition, the cost of the testimony was shared with other witnesses. Many even said that Colbert made some great points. You can see a video of his appearance here.
He told the committee that farm work is "hard" and cracked some jokes about illegal workers and the like.
Here's the video clip of Kelly and King's objections to the Stephen Colbert congressional appearance.