Be sure it is set to no if you want the customer to see the prices for the various products within a category. When set to yes any product found under this category will not display any pricing.  This is great for displaying examples of custom built products that would require a quoted price.

Please Note:  If a product is assigned to more than one category; make sure the price is turned off under all categories or remove the product from the additional categories.  If a product is under another category where no is selected the price will show when found by browsing that category.