Certainly there are other concerns--no argument there. That said, Amazon Prime prices just went up 20%, so Amazon will clearly raise prices if they think the m

Certainly there are other concerns--no argument there. That said, Amazon Prime prices just went up 20%, so Amazon will clearly raise prices if they think the market will bear it. Moreover, "complete and utter dominance" sounds like a monopoly. It's difficult to think of a monopoly that didn't raise prices and/or decrease service once they were established. I would not start a business on Amazon without assessing the risk of tying my fate to a single large vendor, for cost as well as other reasons you cited like Amazon deciding to compete with you.