Diaz was punished for no-showing in a big way, including being taken out of a fight he’s wanted for years and basically his career in UFC was at stake if he wouldn’t have faced Penn, The difference in what he’s going to make fighting Penn in the semifinal with what he would have made against St. Pierre is said to be in the seven figures due to the PPV cut. He’s also out of the title picture, at least for this year. He’s gone from seven figures, even if he lost, to essentially very slightly more than he would have made had he fought Tyron Woodley in Strikeforce for the welterweight title he vacated to get the St. Pierre fight.
For a guy that talks about money so much (or for anyone really), that's a huge, huge loss.