i used Google Shopping to shop for guns all the time. It's the easiest way to compare prices on things and especially guns. You type in the exact model and it pulls up 15-20 results, so you can see who has the cheaper price.
Just because of this move LOTS of small gun shops lost LOTS of business. Most of the gun shops are pretty small mom & pop shops. Their websites are terrible without much SEO, so finding them via regular searches does not always work. Google Shopping brought them business though.
Ammo is best bought locally. Even if it is cheaper online, the weight ends up making it just as expensive as local stores.