Or you really want to go to city X, but the price difference is rent for a month (or more).

I've been looking up flights recently and if your rent is less than 700 you are lucky. You can buy a first class ticket, round trip to the other side of the planet

Just because you've found one ticket somewhere for $700 doesn't mean that's where I want to go or is a time that I can go. Many of my vacations revolve around family events for extended family in another country, so I have limited flexibility in dates or destination.

I'm looking at tickets right now, $735 for economy, $3500 - $6000+ for business, $15,000+ for first class. Fortunately I have a lot of miles, so a 160K mile business class awards ticket is a possibility.

It wasn't just one ticket, i was looking at quite a few destinations, that was just an example. If you plan ahead and shift the departure by a single day the price drops incredibly.

Bullshit.

Unless the airline made a huge mistake, I could have bought a round trip ticket to Thailand for 700 first class. It would obviously be slightly higher in price after fees, 9/11 security fees and whatever else is tacked on. Let's say it's a total of 1k.