The decimal point has got to be in the wrong place? $60 is more like it. These will likely fail while mounting them up.
Pirelli P7's age rather rapidly. If you don't use them, you loose them. It doesn't matter how you stored them. Five years old is about the safe limit of use. The thicker the tread, the quicker the deterioration.
If you shoot them with Armorall, that makes the rubber dry out and crack faster.
They dry any split between the treads. I've had chunks of tread not only separate but come off and leave just the cords.
But yes, Pirelli should make some more new ones. BFG Comp T/A's are as good and they should make some more 15" also.
There is no one left in the world who drives on 15" rims? Wow. Time has for sure passed me by?