I also don't have a credit card that gives me miles. So I cheerfully pay. Perhaps more to the point, I have zero loyalty to a specific airline, so an airline connected credit card doesn't work for me.
Here's something else that's important. I used to be an airline employee. I was a ticket agent at DCA from January, 1969 to August, 1979. Back then the travel benefits, especially working for a smaller airline which I did, were phenomenal. We were almost always boarded first class, so I got spoiled. Even before the current cattle car configuration of so many airlines, first class was, in my opinion, well worth it. Okay, so back then I wasn't paying for it. But now I'm willing to do so.
The secret is to book about three, maybe two months before the flight. Right now I keep on checking on the San Diego and the Seattle flights. At present the fares are higher than I'm willing to pay. In another month or so they'll drop for the flights I want.
I am likewise retired and have plenty of time. That's why I'm happily taking the train from New Mexico to Seattle, which will be four days of travel. I can hardly wait! I've done Amtrak a couple of other times and I'm totally sold on it. Especially booking a roomette.
I have a good friend who cannot imagine spending the money for a roomette, and would take the same trip in a regular coach car. Shudder. I want the privacy and access to a shower I get in a roomette, especially if I'm going to spend more than one night on the train, which I will from Chicago to Seattle. Plus, I'm a really sound sleeper, and I'd honestly be concerned about my purse or overnight case being taken while I'm totally asleep.