When buying things online it a good practice to compare a few sites to see who has the cheapest price on whatever you are looking for. Display screen protectors are an example of a product that is widely available from many retailers and was probably offered as an accessory when you purchased your phone. If you are going to price compare screen protectors it is a good idea to k now exactly which screen protector fits your phone and what other people think about it.
Amazon is a great resource when doing price comparisons because they publish reviews of the product on their website and allow other readers to vote on how helpful or non-helpful each review is. Some products garnered hundreds of reviews and if that is the case it usually means that that item is popular and a lot of people have purchased for their own use and like it enough to write a review about it.
Amazon also is a powerhouse when it comes to price comparisons because they offer free shipping if your order is over $25, which is hard to beat for most other companies. It does figure into the total cost of the product and just because the product itself is cheaper somewhere else the total cost with shipping may be higher.
Sometimes smaller sites will have better prices especially if that is the only thing they do. Larger stores that carry a wide selection of products may let some things fall through the cracks and not monitor price changes as quickly as a smaller store will.
To price compare screen protectors write the price of the protector from the wireless store and then check online to see if the convenience of having it immediately overrules the lower price online. The internet is a great equalizer allowing anyone who is willing to work hard to compete in the marketplace. Take advantage of that hard work and save yourself some money in the end.