Whats the justification for Sonos Amp being 31 times the price you're willing to spend? Niche problem or is the tech inside it worth that?

Everything Sonos is already expensive. It's got the lifestyle-product tax built in.

Anything involving Sonos with wires increases support cost. Simply involving wires produces new ways for people to screw things up (as if supporting their wireless-only customers wasn't expensive enough).

And those who are using wires but not screwing things up gain the ability to expand and improve their audio systems in their own ways, without paying the Sonos tax to do so. They can buy/upgrade whatever speakers they want from any manufacturer in the world, while keeping the same Sonos Amp. That represents lost opportunity, so the amp gets taxed harder.

(The tech inside the Sonos Amp isn't particularly novel. It's just a small Linux box with a trick proprietary software stack and some audio hardware.)

I do like my Sonos setup (have a pair of Era300s, an Arc Ultra, Sub4, and Sub Mini) and now that they've fixed the app issues, it works really well. And the sound quality is good enough for me. I just wish the Amp product was about half the price. It doesn't do all that much more.