Some folks have suggested that our enduro rental seats are more expensive than others. To the extent that this might be true, I blame car owners who don't recognize the real costs that they incur by putting something on the track.
I total up anticipated direct costs (consummables, entry fees, travel) but don't stop there, as do some. I also apply a per-track-time-hour amortization of the cost of building and maintaining the car, over an estimated life of 3 years. (Yeah - feel free to question THAT assumption any way you want!) This accounts for engine rebuilds, safety equipment, and other expenses that are VERY real but not related directly to any one event.
Of course, all deals are "you break it, you buy it" for incidental damage, although we don't charge rental drivers for component failures (like our busted gearbox at the VIR 13) unless DL1 data indicates abuse as a proximate cause.
If you can score an enduro seat for 1/4 (or whatever portion) of the entry, fuel, tires, and other immediate expenses, GO FOR IT. If you are charging renters using that kind of math, call me: I'll rent out my seat in the Golf and come drive your car, the extra $$ in my pocket made possible by your subsidizing me putting wear and tear on your ride.
Because we use a preordinate formula, I'm not shy about sharing prices - figure about $2000 for 1/4 of a 12-hour enduro, with other options being more-or-less proportional based on track time.
K