Not sure what the wife example has to do with this subject. Maybe you meant to say, you married your wife and 2 months later after you find out the prom queen had a crush on you and you could have married her and now you feel like you made the wrong choice?
Back to the original topic - business transactions, it's simple, you agree on price for something, you get it, what else is there. You asked me how I would feel. Well, it just so happens I was in a very similar situation with Tesla including the $5K package for free on the Model S just few months ago (price went up by $2.5K, so technically car identical to mine would be $2.5K cheaper 2 months later). It didn't bother me at all. Maybe I just don't get it. What other people have or don't have doesn't affect my satisfaction with what I have. I wish everyone would have a Tesla, even the poorest drivers - I would hope it would make for faster moving traffic, so better for me. I make my choices based on information available at the time, and I don't look back. As long as I can honestly say to myself that given only the information I had when I made the decision, I would make the very same decision again, I sleep fine.
This kind of reminds me of people who sell their stock options from companies they work for, and then are sad if the stock goes up. If the stock goes down, that makes them feel like they made a great decision to sell when they did, but somehow they don't factor into that feeling that the rest of their stock options have devalued because the stock went down, and if the company stock is not going well they may also loose their jobs. Basically, they are rooting for their own detriment in order to justify some one time sell decision. Completely irrational, just like people here complaining that someone else will be able to get a more affordable Tesla.
But yes, I will agree that majority of people are irrational. Recently a very large poll (>1M people) about self driving cars showed that majority (>76%) people would support autonomous cars to implement a policy of minimizing the number of deaths, even if that meant killing passengers (e.g. run over 2 pedestrians to drive a car with single occupant into a concrete wall, choose to kill the occupant). However, when the question was turned around, people were asked whether they would purchase such a car or a car that would protect the occupants at all costs, significantly less than half of those same people said they'd pick the car that maximized death. So yes, there is a very significant portion of the population which is irrational and inconsistent in their own ethics even.
I was simply trying to point out the irrationality of the complains. People would be much happier if they were more rational.