The reason the US car industry does not want a $25k car is that the financing opportunities are crap for a car of this low cost.
In the same way that airlines exist to offer you a miles based credit card, the US car dealerships survive by offering you a loan for the car. Or perhaps, a car to go with your structured finance opportunity.
From both an economic and quality of life point of view, you are better driving your car until it starts to get slightly unreliable and then quickly trade it in for a slightly newer used car. Buy a 5-10 year old car, drive it for 5-10 years, then trade it in for a 5-10 years old car is probably pretty close to an optimal strategy.
With Apple stuff, waiting more than 1-2 cycles means you've missed the ability to recoup most of your costs AND you got to use an old device for an extra year... yay?
If the phone only lasted 1 more year, then the resale price of the phone would reflect that. Either the collective market of buyers lacks the information to evaluate this (doubt), or you got lucky finding the one buyer willing to overpay.
You also always pay full price, because when you buy a new phone (or anything), you always have the option to buy the used or keep using the old one. Cost is opportunity cost, which is defined as your choice minus your second best choice.
While this is true, desirability in the used market doesn't work linearly. Apple devices fall off quickly in value after 2 years. If you buy early in the product cycle, selling as soon as you can buy the next year's model has proven to be the most economic way, because resale on last year's model is still great but 2 years ago is in the tank.
I've been upgrading yearly since 2007 and my spouse waits 3-5 years between phones. Doing the math, over the years I've spent less overall because of the value of sales when I trade up vs. their phone was worth sub-$200 when I sold it recently, because it was older than a few years.