Your price sensitivity would rationally be set to look at the opportunity cost across spheres of spending- an extra $100 on your flight is 10 days of parking tickets or something like that.

It seems like you're falling to the "Mental Accounting" [1] fallacy, wherein you create buckets of money but forget that they're fungible. You splurge in one area and cut back in another. [0]https://en.wikipedia.org/wiki/Mental_accounting

No, my point is that different decisions in how I park can make a bigger impact on my bottom line than whether I fly Southwest or American First Class. I take a real travel vacation maybe once every 3-4 years.