Not just Chromecast -- they also completely ban Apple TVs.
It's pretty sketchy.
A great example is their Diaper.com fight with their launch of Amazon Mom [0].
[0]: https://www.bloomberg.com/news/articles/2013-10-10/jeff-bezo...
>I had a period of about 3 months where Amazon just couldn't deliver to my house.
And Amazon can also ban you forever from their service, for example if you return too many things in a short period.
Imagine if that meant you couldn't buy anything at all because there aren't any competitors.
Loss of selling privileges can be a big problem too, and incredibly hard to fight.
The store I work for once lost selling privileges for spurious copyright claims regarding books we had bought directly from large established publishers. Even with the publishers themselves (and sometimes the authors, too) writing on our behalf to state that there were no violations, it still took about two weeks to regain privileges. During a busy season, two weeks is a long time to be without profits for a small retailer.
Not to mention that price isn't the only reason why monopolies are bad. I had a period of about 3 months where Amazon just couldn't deliver to my house. They switched to using their own carriers, and they would just never be able to find my place. I actually had a hard time finding another retailer that would ship to my house for less than double the total price of some of the things I was buying.
Plus the (very real) threat that they can just remove an item from their store for any reason (the one that comes to mind is that Amazon doesn't allow anyone to sell chromecasts' on their store. Rokus, Fire Sticks, and various other streaming "devices" are fine, but chromecast is banned completely) means they also have a monumental amount of power to hurt anyone selling through them at a moment's notice.
I'm not in a position to say whether or not Amazon is a monopoly, and I wouldn't even know the first thing about solving the problem, but IMO the fact that they haven't raised prices isn't exactly proof that they aren't a monopoly.