Going first class

Airfares make no sense.
How much does it cost to fly New York to London, roundtrip, in say, December, on a major airline? I found prices from $640 to $43,000. Same dates, same airports. Okay the $43k flight does take you through Hong Kong, but nonstop flights still range from $640 to $19,000. This makes no sense.
Prices vary by date, by airline, by number of stops, and by website. But the biggest differences are between classes: Economy to First. Travellers on the same plane have paid vastly different prices. Why? Comfort.
I've heard that airlines are phasing out first class because it's a money loser. Huh? They say it's because no one actually pays these exorbitant prices. Companies make deals to fly their employees for less.
I've also heard that airlines lose money on economy seats but make up for it on first class.
Both of these cannot be true. Somebody's lying.

Sleeps on a plane

I used to wonder why anyone would pay for anything better than economy seats. That was before they started shrinking the seats and my bones got some age on them. I still, for short flights of three hours or less, think economy is perfectly okay. I'm a medium sized woman. But for long flights, I'm going for the upgrade.
Some airlines have added a new class called Economy Comfort, or something similar. I took one of these on a recent Washington to Amsterdam flight and found the extra room to be well worth the extra $165.
 Some airlines are upgrading Business Class until it's as nice as First. It's all about room, and how much your seat reclines. For overnight flights, there's nothing like a bed. I like to use Seatguru and compare. But there is a difference between "lie-flat" and "flat bed" seats. Lie flat seats do flatten out but they're still on a bit of a tilt. Flat Bed seats are better for sleeping.

Let me tell you about a perfectly wonderful Upper Class trip I took on Virgin Atlantic. VA is not paying me to say any of this. It was a splurge, but not a huge splurge. I paid a bit more than double what it would have cost me to fly Economy.
The flight attendants greeted me with a glass of champagne and I suppose I could have drunk myself blind for no charge but I didn't want to arrive hung-over. My seat was more like a little suite, with everything I could possibly need built in near my head. I had chosen the "Sleep Zone" so I wouldn't be disturbed. They gave me jammies and a place to change, a pillow and blanket of course, and a toiletries kit (which they give everyone) It was so nice I could hardly get to sleep, wanting to savor the whole experience. Nevertheless, I did doze off and arrived in London feeling ever so much better than I usually do. You can go to the fast lane for Immigration.
To freshen up before hitting the streets of London, I went to the Upper Class lounge in Heathrow, where they take charge of your luggage while you eat anything you want for breakfast, shower in a truly luxurious private room with big towels, a hairdryer, lotions, etc, and hang around until you're ready to leave. You could even get a manicure or a facial.
Totally worth it.
Advice? Start with Kayak or whatever to get an idea of the price range. Choose an airline and go to their website to book. Consider upgrading on long haul flights. And as always, don't forget to bring your sense of humor.