When did we start talking about sub-$1000 phones as cheap?

After the era of iPhones ranging in prices from $399 to $699, or a little bit more, and the Samsung Note ranging from $599 to $699 (which was not cheap at all, and is not now), we suddenly found ourselves thrown in a new invented era called the ultra $1000 phones. Not only that, but we now have a new category, which was not present a few years ago, which is sub-$1000 smartphones.

In the more “reasonable” pricing times, there were the newest devices and those that were more economical. Then appeared the flagship term, which meant that companies would start to create two different categories of a phone, a higher-end one (which was expensive) and an average one (which looked a little bit the same, but with lower specifications).

After that, we started hearing a new term; mid-range phones; and again, this meant that a third category was created: We had the flagship, the mid-ranger, and the “cheap” phone. What really happened is that companies, like Apple, Samsung, LG, and others, moved the pricing higher; giving the original flagship prices to the mid-rangers, and the price of the mid-rangers to the economical ones, which gave the managers of those companies the chance to present us with flagships that were nearing the $1000 point, such as the Samsung Galaxy S8 and Note 8 (min $899 and $930 respectively), and the iPhone 8 and 8 Plus (min. $700 and $800).

Finally, we could clearly see the evil master-plan as it was laid down on us when the latest flagships were released, now phones cost more than $1000, this is how it is. What about mid-rangers? Well, they cost between $600 and $750, and cheap phones? Well, they can be anything less than that, it depends.

My question is: When did $600 and $750 become the equivalent of an “average” phone? And when did it become “normal” to spend $1000 or more on a phone? And Why? And How?