"You cannot handle the truth"

70 hours is probably a years worth of listening for most of us.  The guy probably just wants something new, or something that works better for his system, or he needs the money.
I have been burned both buying and selling audio equipment.  As far as I'm concerned, the used audio market is fraught with peril.  Audiogon does as good a job as possible, but I think it is a better idea to avoid impulse purchases, choose your equipment carefully, and keep it for a while.  If you just can't live with a certain piece of equipment, sell it or see a psychologist.

1.5 hours a week.  I posted about this on another thread ( https://forum.audiogon.com/discussions/what-a-sad-world-we-now-live-in/post?postid=1752367#1752367 ).

Of course, that is for those of us that work and have lives outside of audio.  I think I may edge a little higher than that, but not much.  And I enjoy this hobby as much as anybody.
Now that is actually sitting down to listen without distractions.  I may have the radio on in my car, or listen to my local classical station (WILL Urbana IL, Tivoli Model 1) when I'm making pizza dough, or even catch a short tune on the elevator at the doctor's office, but I don't count those sessions.  That's just background music.