Years back I bought a used Herman Miller Aeron, it was way out of warranty but also way cheaper vs buying new. Totally worth it, I do like mesh chairs and the Aeron is one of the best in its class. Plus it has a ton of adjustable levers if that's your thing.
The only thing I screwed up was the sizing, those chairs come in different sizes and I probably should have gone for one size smaller but it's not a big deal. Sizing is something to keep in mind when chair shopping, they're not all one size fits all and you may want something specific to your height/weight for better support.
Doubt it, kind of assumed once the mesh breaks the chair is done. Maybe someone handy with that stuff can rig up something to fix a chair like that?
To be fair the mesh seems pretty strong, mines hasn't broken thus far.