When is an amp ‘just too old? ’ To buy?

Hello sports fans!!

I’m seriously tossing around the idea to get into another amp (s) as I’m simply not playing mine as I should. 20 hours in the last year or so is about all. I’ve been using both my office and now BR systems far, far more as they’re handier and simpler to manage now.

Switching speaker wires, and re-checking bias from extended lengthy periods of non use causes me to not use my monos enough to keep them or so Im thinking.

Add to that my vision is apparently going away now at a faster clip than I’d prefer too …. It all adds up… so there they sit. 20 hrs. over a whole year. It’s embarrassing.

So I’m thinking SS. Or self biasing amps now as replacements, IF I decide to go that way and it’s looking more & more as I will.

I’ve always thought amps under 5 yr and preferably under 3 or less, as the ones I’d prefer to take a shot with, but am seeing more and more amps now with 5, 6, 8, 9, even 10 years from date of production and am wondering, just when is an amp (s) old enough to forget about or when one should really consider some other amps.

Do you all feel SS amps have a different criteria than do HS amps in terms of longevity?

Or is it vice versa, with tube amps lasting longer, generally speaking?

How old is just too damn old! As it relates to amps for sale… in your opinion, of course????

Thanks much.