I believe what he means is that if you divide the total cost of $1020 per mile that they last....then it would turn out to be the cheapest since they last a long time. The tread wear was something like 300 I think. I used to have a G35 and ran them on the SCCA course......not too bad. It depends I think on what you want. If you are looking for a tire just to cruise on and works okay in the rain...then these were fine. If you are looking for performance tires...then because of the harder compound, of course these will not grip as well as the softer performance tuned PS2's.
As mentioned, the PS2's were designed as OEM tires for the Viper, so the tests and the data were based and utilized from/with the Vipers characteristics in mind. The BFG's were designed for some performance and wear but for a broad range of vehicles that could use the sizes that BFG were going to produce.
It is what it is. PS2's are a better performance tire and the BFG's are a better longer wearing tire. As long as the individual understands the limitations of their abilities and the products that are used on their vehicle (Viper or otherwise) I think that they will be satisfied.
Best of luck and order them from Jon. Prices cant be beat and service is really quick.