I thought that number was a little high, but once you add the prep (probably the majority of the cost) for (2) karts (they had a backup), paid employees, preventive maintenance on the semi, Lodging/RV, pit sites, and all the other little costs. It will add up. I could see a good portion being spent on parts and testing to get the right setup, since Crandon is very different than Loors tracks. Obviously you could do it for less, maybe these guys are big spenders.
I live 120 miles away, and it usually costs me $1000 to $1500 total for fall crandon. Grenaded a fresh motor one year, that added another $4000. I guess thats why $30k wasn't super outlandish to me.