$8k sounds hard to justify given the market value, maybe consider the alternatives for replacement - it seems resale on all electrics is pretty low, so maybe better to put that $8k toward a LEAF or Volt coming off lease? Any chance a more dedicated/ambitious i-MiEVer (I'm sure they're all here from time to time
- chime in!) will pay a bit for a carcass to strip, or maybe even have a wreck with a good MCU inverter to sell? (given our low numbers, I realize this may depend on near-perfect timing, but worth a thought).
That's likely the way I'd go, anyway. Actually, due to other life circumstances, in this scenario I'd be mostly to get what I could for salvage and buy a new Prius Prime, but I wouldn't consider that general advice.