Autozone and I have a love hate relationship. Here's why.
1: Pricing. As an example a bottle of Lucas Fuel Injector cleaner is at least $1 higher here than at their competition.
2: Batteries. Shopping around for a battery netted me a $30 savings over what Autozone wanted to charge.
3: Quality: Autozone's lifetime brake pads and shoes have just not held up to regular use. Pads purchased from their competition have held up and are quieter.
4: Service: Quite frankly this location seriously sucks with attitude, slowness, and just plain sloppiness.
5: Cleanliness. Parts Stores are not bastions of cleanliness but this one is cluttered and dirty compared to other Autozone locations here in Las Vegas.
In short, sometimes they have what you need at a price that you can't beat. But that's rare. More often than not your best bet is to pick up the phone and call around. You can often times find parts for less elsewhere.