In the case of our local stores (I am not based in the US), I always take what the stores "recommend" with a grain of salt. More often than not, they would suggest a lot of items that are 1) not compatible, 2) low performance and highly-priced, 3) does not suit your needs, and 4) does not suit your tastes.
Some stores offer items that they urgently want to remove from their stocks (esp. items that are already phased-out or very slow-moving inventory components). This is coupled by "guaranteeing" such items as "good quality" or "that's the last stock we have so get it now before someone else does."
In short, do your homework first and read a lot of user reviews of the items that you wish to purchase. Consider talking to them about first looking at the items first hand (and if they let you open the box to get a feel of the actual item itself), without any commitments yet. You should already have a working budget at hand (i.e., the price you are willing to pay such items). If you feel the items you are looking at are acceptable to you, just ask how much they are selling such items for (if there's no price tag, that is). If such item costs more than your budget, then, kindly ask them if they are willing to sell such for the budget you have.