A few thoughts on Amazon's acquisition of Whole Foods...

So Amazon bought Whole Foods and the corner of the market dedicated to groceries lost its mind. I can understand that. It was a bit of a surprise out of left field. Earlier today I read an article on Vox about the whole thing (find it here), in which they do a great job of breaking down why everyone in the produce business is on edge. In a nutshell, amazon doesn't hold cash, they reinvest. Furthermore, their business model appears to involve growing the reach of their company while incredibly sacrificing profits. This is believed to bode for inconceivably low prices in the future for Whole Foods shoppers, and that is believed to spell the end of profitability for any other grocery.

All of this brought a question to mind.
In history, how many widgets or products have, over time, NOT gotten cheaper or seen their profit margins get slimmer?
Immediately, I thought of gold and other precious substances, but these are raw materials, not an end product. Admittedly, many grocery items could be considered raw materials, too, and that is part of what makes this question interesting.
Automobiles were once for only the richest among us. Now we sell them on craigslist and donate them to Goodwill. I could give other examples, but you have better things to do.
Should we be shocked that the produce part of the market appears to be in for a dip in profits? Is this part of the natural evolution of the market or is this acquisition of Whole Foods destined to be an outside agency causing havoc on the market, and requiring other outside forces to come to the rescue? Please share your thoughts in the comments.