A short flight, of about 800 miles. I flew from SFO to MNL, (about 9,000 miles) 3 years ago. I got a random upgrade to business class. I was told a business class one way ticket, was about $2,000. To rent the entire business class cabin, would be about $56,000. I have to admit, it was the best flight I EVER had. 👍
My British-born wife lived with me in America for 10 years before we retired to Spain. She would spend a month in England visiting her family each year and I always booked a first class ticket for her. It’s not just the meals, it’s the ability to stretch out on the long flight. Plus, if there’s a layover like when she flew on AerLingus, she got to wait in the first class lounge instead of having to fight to find a seat in the main terminal. We only fly shorter trips nowadays (we just got back from Brussels, for instance) but we still buy access to the first class lounge so we can relax while we wait to go home. To us it’s well worth it.
Years ago you could get free upgrades to First Class but not now ...