Repairability and build simplicity were a big factor for me purchasing the Meze 99 Classics. I can't say how long they'll end up lasting, but you can visibly see almost every screw in them. Even if I can't find Meze-branded replacement parts for the rest of my life, they seem modular and simple enough that I could probably at least limp them along for a LONG time.
They aren't cheap, but they are also some of the best headphones I've ever personally used. I don't make any claims of being an "audiophile" or whatever, but they're like the headphone equivalent of using my Kali LP-6 monitors.