It is not the shop especially that I look for...it is the manufacturer as said above. If a particular site won't tell me the manufacturer, then I won't purchase (i.e. Keepsake). You cannot tell the quality by the design because there are knockoffs.
That said, shops do matter. Customer service and friendliness and reasonable shipping are what it is all about more even than price. We all have our short "go to" list, but sometimes you are looking for a certain thing and have to try others. Good way to make new friends.