It depends on why it is low priced. Many discount food stores have food that is out of date, spices are dusty etc but if you go to say, a bulk food store you are paying lower because you are not paying for packaging.
Buying bulk saves money as well as helps the environment. As long as the store isn't seldome used, things should be quite fresh. The best places are your local nature food stores. You can also order spices and herbs online. My favorite site is www.mountainroseherbs.com. Their herbs and spices are ultra fresh and so inexpensive compared to the little jars.
Another thing to keep in mind with cheap stuff, food or otherwise, is production; where it comes from, how the people that grew it were treated, what chemicals were used, etc.
For the best deals for you and the environment, shop fresh and bulk and local whenever possible.