Entirely personal
I believe the choice is entirely personal. What is worth it for an older couple on a trip of a lifetime, which perhaps does not indent into their personal finances significantly, is simply not worth it for a backpacker on their first venture to North America or Europe (it will cost them 10 days of holiday).
My 2c. If I fly for business, the company believes it's worth me having a good nights sleep so I can arrive and work the next day - and they put me closer to the front. If I fly alone or with family, I never, ever pay beyond economy. I simply have other things I do with the money, better restaurants or experiences etc. Perhaps when I get into my later years I'll pay the premium, but at the moment, I don't know how people who are young and able bodied justify it! And yes, i'm well over 6 foot tall, and flying in economy hurts.
Lastly - for freight - consider unaccompanied if you have lots, also consider other airlines who may possibly be more generous (though I love flying AirNZ up to YVR - I've been in the nose a few times!)