I'm Traveling PVG-LAX on XN economy award ticket, 32.5k miles + $34.10. I was originally traveling on a later date and came to the airport and was given a boarding pass for today. In the lounge I checked my flight online and was offered "Business First Upgrade for $469" with a message that said there were 10 seats available for sale - it was kind of a no-brainer offer to me, so of course I took it. After that went back into the itinerary to change my auto-seat assignment (this time on my mobile, from 6C to 6B), I was offered yet another upgrade to Global First for $1130, which I declined.
This is going to sound hypocritical, but I kind of have a problem with being able to buy PVG-LAX for $500 and a few miles. As a 1K I like the opportunity to utilize my GPUs, and if they're selling cheap upgrades over someone on the waitlist it just seems a little unfair. It's particularly shocking that I could fly PVG-LAX in Global First for 32.5k miles and $1600.
So yeah, I took the offer, but wow, it's kind of stunning to me.