The 2017, if no maintenance was EVER done, should have a brake system flush for about $200. It it's just been left alone since 2019, then aside from maybe still needing the flush if it was never done, it should be ok. Brakes on Leafs last a long time because of regenerative braking. They do get surface rust on the rotors while parked, though, so what feels like grinding brakes is usually just the rust, which should go away after a few stops, unlike the noise from actual worn out brakes. If the BMS update was never done, or was done many months or even a couple of years ago, then 11 bars should mean that the pack is good. You should have a dealer or Nissan's EV Help Line run the VIN, to see if the update was done. Make sure that the heater throws out lots of heat. Which packages does the 2017 have? A 'stripped' SV should still have the heat pump, but the Premium Package adds a great 4 camera parking system, and a better stereo, so that increases the value of the car.