One thing I cringe to buy is tires, especially for my minivan. The last flat we had was due to a nail and that cost us $150 on the day of my sister's wedding! Frustrating us at the time was that the tires were relatively new to begin with, having only been on the car for about six months. Ugh! With winter upon much of the country, you may be looking to purchase new tires.
I found that Costco has a deal on Michelin tires right now. From 1/5/12 through 2/1/12, you can get $70 off a set of four Michelin tires at Costco. Definitely check to see if they stock your tire or if they'd need to order some if you're pricing tires for your car.