Adding up your clues, purchase price indicates greater than 50% depreciation with 5000 miles from new, and the driving range when battery is severely degraded, is your ZEV a Dacia Spring?
If the average mileage is 5,000-6,000 per year, then a battery that is likely to do 200,000-250,000 miles without a significant degradation really isn't going to concern anyone as the car will almost certainly have fallen apart before it reaches that time. It could take 40 years on a small car to reach that mileage!!
Only people doing loads of miles (e.g. taxi drivers) have any need to worry about the condition of the battery as they're the only people likely to get anywhere close to the point where the range has dropped enough to perhaps impact their ability to work.



