I personally stay loyal to one shop for maintenance. But for pedals, clothing, accessories, etc... I shop around. You have to get what you want and for the right price. If the shop I get my bike worked on at has it for the a reasonable price, I go there first. Today I had to go to a competitor to get my husband a helmet for his birthday tomorrow because my favorite shop was out of his size. A lot of times we order clothing from the internet because it is a better value and selection.

My opinion- stay loyal when you can and don't feel bad for buying what you want where you want.