As you're passing all those car dealerships on I-10 after a shopping trip to Katy Mills, the phrase "a little drive will save you a lot" will echo in your mind. Whether you just purchased a pair of designer shoes or those worn-and-washed jeans everybody's wearing nowadays, most likely you got them for a fraction of the price those Inner Loop suckers paid at some River Oaks boutique. Nearly 100 stores at Katy Mills are outlets, which means starving fashionistas can buy cool clothes and accessories for bottom-of-the-barrel prices at places like Off 5th Saks Fifth Avenue, Neiman Marcus Last Call, Nine West, Banana Republic, Kenneth Cole, Guess? and Polo Ralph Lauren. Even bookworms can find an apple of a deal at Books-A-Million. In light traffic, the drive takes a little over 30 minutes from downtown. And the extra gas money spent getting there will be marginal compared to what you save at the end of the day. Driving a hard bargain never came so easy.