How much would you pay for a modern tech 15" 60 series performance streetable tire?

I guess..I don't see an issue with an all season tire if it gets the job done. If it won't get the job done on the street, you have a chassis problem, not a tire problem. Like I said, I run all seasons on 2 of my cars. You'll run out of balls before they run out of tire on either of those cars. My old BMW MC40 would pick up the rear inside tire on the street and that had all seasons on it.

Don't think I'm knocking your car by saying this but how hard are you really pushing that duster through the corners on the street? Does it ever see road course or Auto-X time? Hoosier makes tires in the size you want for that application but they aren't really for DOT use although they are rated DOT legal. They are borderline slicks for road course and Auto X.

What mods have you done to improve the handling of your car? AlterKtion? Facotry style upgrades?

Fair point, of course. Any kind of street use should be handled by all season tires with ease. Of course, saying this publicly makes you seem like kind of person who would be happy with a Prius. ;)

Come on now...ANY car would benefit from more grip. If for nothing else, braking is dramatically improved with better/more modern rubber.

I'm starting on suspension and chassis
bracing for my car now. I'd love it if my next set of 15s were actual performance tires.

Hoosier Street TDs are a tire that I recall...but I believe that they're old school bias ply...not sure how they compare to modern radials.