I guess the real problem is pricing: right now it is buy used, then swap batteries for 8-10K? No wonder the car deprecates.

I vaguely remember a guy swapping modules of the battery of a Prius at home for peanuts, because the dealership asked 4K for the same service. There are a few places that do a battery refresh for 1 or 2K (eg. texashybridbatteries.com). In the future this might be a good business, today it seems to be a Prius thing... because it was the most successful car a while ago.