CVS is currently running one of two sales, depending on your location. Some are selling Wheat Thins for 5/$5 (making them $1 a box) while others are running 2/$4 (making them $2 a box). If you use this free $1 printable coupon (that's a Firefox link, here's an IE link), then you'll either get a box for free or for $1.
If you want to check out the price before heading to the store, use the store locator to look at your location's weekly circular. The Wheat Thins are on the second or third page.