I think with tires, you really do get what you pay for.
Nearly 6 years ago, I had a set of four Michelin Green X 225/60R16 tires installed on my car at Costco.
No, they weren't cheap. I think even with the Costco discount, the total in 2010 was somewhere in the range of $500-$600.
Long story short, they lasted about 5 years, and I'm not even sure how many miles, but it was pretty close to the warranted figure (circa 70000 miles IIRC).
I lost one Michelin last fall to a bolt through the sidewall (still not sure how that happened). By this February, the other three were looking not so good, with lots of small cracks. One was leaky enough that it was losing a few PSI each week.
I remembered all this when tire-shopping. Initially, I thought about buying some cheap Chinese tires, but in the end, I just couldn't. Again, I laid out the better part of $600. No regrets.
Granted, not everyone has the budget to be choosy. Like the guy who was driving his beat-up Kia in the Walmart parking lot last week, with a donut tire holding up a rear corner of the car. And a non-working tail light. And a missing front bumper cover.