Somewhat of an aside...
I think the mindset of the folks complaining about the current pricing structure for iPhones breaks down to the expectations that Apple had set in earlier years compared to the new reality. Here's what I mean.
From the iPhone 3GS through the iPhone 5s, anyone who wanted a flagship iPhone paid the same price (with adders for storage space). It didn't matter if you were super rich or a regular guy, you paid the same $650 (or $200 subsidized price) that LeBron James paid (yes, I know he was a Samsung shill).
Apple expanded the flagship offerings starting with the 6plus. The 6 was still $650, but if you wanted a bigger screen, you could get it for $750. At that price, if a regular guy wanted to "keep up with the Kardashians", it was only a 15% bump. Not too bad.
Then with the introduction of the X, that's when the complaints really started to come in. Apple decided to take the flagship up a level or two. The put in bleeding edge tech and a new design philosophy that really divided the user base. Then they slapped on a $350 price increase (from the iPhone 7) for a 54% price increase compared to the previous non-plus flagship. Now, it was much much harder for regular folks to afford the flagship iPhone. It was no longer a reality that regular folks could get the same iPhone that the rich folks could get.
And I really think that, subconsciously, that rubbed many users the wrong way. The X wasn't a new product (even though in many ways it was) in the public's mind. It was the new flagship and it carried a really big price tag.
Opinion #1 - perhaps, in hindsight, Apple could have marketed the X as an offshoot of the regular iPhone/plus line. Maybe the expectation that the flagship iPhone was "affordable luxury" could have been maintained. The iPhone X line could have had a psychological separation simply using a different moniker.
With the Xs/Max, Apple has put an even more expensive option of the table, combined with the available option of 512GB, makes the price comparison skew even worse, from a perception point of view.
Opinion #2 - the Xr was meant to allow a lower entry point for X level design. Instead of pricing the new flagship design at a price point that most people can afford (or at least had been accustomed too), Apple releases an iPhone that looks and functions (mostly) like the flagship. For Apple, I think they feel that this is a win-win. Price conscious shoppers have an option for a flagship-design phone at a more affordable price point. Price-is-no-option shoppers can spend to the moon and get the latest and greatest. We'll see how Apple's bet pans out come this February when they release numbers.
Anyways, this is probably a long winded way to say that many of the price-complainers probably, IMO, lament that it's getting more and more costly to own the flagship ... as they have done every year since the iPhone 3GS.