Inverter Converter replacement: new or used?

Help! My 2012 Prius C showed a "check hybrid system" message after getting an oil change recently. I had it towed to a mechanic and he said that according to code "P0894" the inverter converter needs to be replaced and quoted me just over $3200 for parts and labor. I'm hoping y'all can help me to answer a couple questions:

Is this fairly common at 200k miles? Or is there a chance I'm being swindled?

If the part really needs replacing is it the kind of thing that needs to be new? Or could I purchase something refurbished and/or used?

And finally here's some context: vehicle was purchased new and has never had any major issues. I've been careful to keep up on the maintenance and have even recently had it checked out by a trusted mechanic before taking it on a long roadtrip across the US (it got an excellent "bill of health"). Current milage is just below 200k and it's been driving fine for most of a year after that roadmap.

Any advice would be super appreciated, thanks!