It seems like I've been paying about $100 per tire ever since I started driving way back in the late 70's. This price has held true as recently as a year ago when we replaced the tires on my wife's minivan. And I've never bought bargain basement tires.
Yesterday I bought new tires for my compact pickup and they cost $185 each! Zoinks! Lemme sit for a minute, eat a few Scooby snacks, and catch my breath here.
It must be because these tires have a max inflation pressure of 80 PSI, whereas the tires on my previous vehicles ranged from 35 PSI to 50 PSI. More air = more $. Now that I think about it I can see the relationship, but there was a bit of sticker shock at first.