This is a ... weird way to look at it.
The increase in fuel costs affects you roughly equally whether you negotiated or not - so it's not at all a factor in the decision making process (unless simply not owning a car is an option). I mean, the price of goods went up a lot too due to rising fuel costs, but we don't consider those when buying a car, right?
> The one and only way to save money on cars is to not buy them.
Ah, your reasoning makes sense now. Unfortunately, not buying a car is not an option for many.
> 1% or 2% difference on the nominal purchase price amounts to nothing in the big picture.
I would strongly recommend taking a course (or reading a textbook) on engineering economics. Your way of thinking is precisely what they caution against. If anything, the fact that things have gotten quite expensive makes it more important to cut costs where you can.
Fortunately, that's not me. I've been keeping all financial records for all non-cash transactions for over 15 years, and so I know exactly what I've spent on my car - fuel, repairs, addons, everything. I've posted breakdowns far down in my comment history (perhaps in the last year - not sure).
What I can say: It's not even close to whatever Edmund's TCO calculator reports - so I'm a bit wary of these estimates. I'm not frugal, and I'm not a car guy, and I do whatever the mechanic suggests.
The notion that the amount you can save is only $500. As several commenters have pointed out, it could be a lot more (pre-pandemic).
> But no amount of analysis could have told me that at the time
That you are "making" money on this car is irrelevant to the analysis. Just as totaling the car within a few months of buying it is irrelevant to the analysis. You'd still have anywhere from $500 to $3000 more in your pocket regardless of the amount (or direction) of the appreciation. You'd still get the negative depreciation you're getting now.
Again: I really recommend reading an engineering economics textbook.
> a difference of $500 either way on the purchase would have been utterly irrelevant to my happiness and well being.
Well clearly, if $500 is irrelevant to your happiness, then it is irrelevant to your happiness. No one is trying to convince you otherwise. What people are pointing out is that the $500 (likely a low estimate) you are down has the same financial impact on you as buying a Pepsi and getting charged an additional $500 for the single Pepsi. That the latter case may make you upset (or not) is up to you. We're not trying to make you feel better - we're pointing out the financial outcome is the same.
Of course, if you're simply trying to say that it's not worth $500-3000 spending the effort to get a better deal - that's totally fine. But that should be phrased as "$500 wasn't worth the hassle" as opposed to "It shouldn't matter because it is a small percentage of total ownership cost".
The one and only way to save money on cars is to not buy them. The true cost of car ownership is massively, woefully underestimated by virtually all drivers. 1% or 2% difference on the nominal purchase price amounts to nothing in the big picture.