$75 ..jesus
thats one hell of a rip off, we use OFN (oxigen free nitrogen) everyday for pressure testing refrigerant systems due to it being a inert gas (well not totally inert) you dont have to worry about expansion due to changes in heat etc so a constant pressure can be held for long periods of time, as for not having moisture in your tyre then this is enevitable unless he pulls a vacumm in there first before filling with OFN, were talking about formula 1 sort of performance gains here though, as the previous poster said if their air drier is working correctly then this shouldnt pose a problem..
$75 worth of OFN would do about 30/40 cars!
if my dealer offered me this i would go down and personally punch the dealer principle in the head ...twice ..maybe three times...