I've bought countless bike items on Amazon and never had an issue.
Amazon doesn't always have the best price, but what I like is the Amazon web site is often easier to navigate than most on line bike retailers. Often times I will start on Amazon to find stuff I want, than end up ordering from somewhere else. This is especially true if I am ordering multiple items and Amazon has them coming from multiple retailers. I would rather see everything ship from one location, minimizes waste.