I go online, find what I want, then print out the page and bring it to my LDS to find out if they can come within $15 or so of the online price + s/h. Sometimes they can do as well, or better, than online. Sometimes they tell me I’m better off getting it online.
But I always like to go to the LDS to discuss it. Find out the merits of the product, whether or not the brand I’m looking at has any deficiencies or another brand, though slightly more expensive, makes a better product, etc.