...but the teacher recently told us how she's getting migraines and anxiety at least partly due to the poor quality of the tech students are using...
Fair warning: Harsh response incoming. I feel like my response is justified, as someone who teaches private piano, and is a public school music teacher who has been teaching entire classes of students remotely since March:
Your piano teacher is either making a very poor sarcastic joke, or she is an elitist asshole. Private lessons are already a thing that not every family can afford, and the fact that she is being melodramatic and shaming people into spending more money is disgusting. Would a better mic help students be heard? Sure.
You can afford a new mic, but that may not be true for others. Does that mean they care less about their children's music education, in her mind?
I hope she's an exceptional teacher and your kid loves her and is making great progress in proper technique and musicianship. If not, I'd drop her like a bad habit. This kind of thing makes my blood boil. She would survive all of 10 seconds in public education, where we teach
everyone. There is a hotshot private violin teacher who teaches some students in my school district, and she didn't let them perform at a school orchestra concert because their weekly lesson was that evening which she wouldn't allow them to reschedule. She's an asshole who thinks the world revolves around her, too.
<takes a breath>
edit: I took a look at all the interfaces and they all look interesting, but the Motu M2 looks like maybe something I should consider. XLR ins, Preamps, phantom power, and USB-C output... hmmm... just need to get a pair of mics then. If this remote lesson keeps going for a while I'm going to be mighty tempted to get this and a couple mics...
It's a fantastic unit, and the performance is hard to believe for the price. If you are interested, can give you my contact at Sweetwater who has been able to get me some hard-to-find items that are advertised as out of stock.