You dont remember the days when a set of SEDAN tires were $30? These days sedan tires can be had for less than $20. I wasnt racing 1/8th back then, but there was a time when tires were about $50 a set. The tires you talk about are a bit more expensive because there has been advances in materials, the new tires with carbon in the plastic are going to cost more simply because a material(carbon) has to be added.

I actually think its less expensive to race now, than it was 3 years ago.