Out of curiosity what are the cost differences

I am always bemused by guys trying to get a license for a car that won't run the number. Seen it multiple times at Irwindale.
As opposed to guys sneaking in a few passes with a car that clearly needs a license, and LOTS more safety equipment.
(The guy with the twin turbo 427 Ls, in an S10, that went 125 in the eighth..... with a lap belt..... and nothing else. Got bounced before he got back to the timing shack)