I've been very disappointed in the lack of aftermarket battery and bms replacements for older electric and hybrid vehicles. It seems like I should be able to jump on Alibaba and get a giant li-ion battery bank + bms and drop it in a 2005 prius and have a cheap, relatively high-range vehicle.

I ran the numbers for here in CA. Even just comparing Gasoline pump cost vs Electric charging costs, the electrics are roughly equivalent to a car that gets 45mpg. Maintentance is of course cheaper for electrics because they don't need oil changes or timing belts or spark plugs but that doesn't mean electrics don't have expensive maintenance plans attached if sold as Teslas.

Right now Electrics still cost about 10K more than their gasoline counterparts.

Overrall, I still think a Toyota Prius with 55mpg will be cheaper to run overrall than an Electric, taking into account total cost of ownership.

The key thing to remember is that EV's are going to keep getting cheaper due to decreases in the battery costs, while ICE's are going to stay the same. From what I have read, the experts think that around 2022-25 EV's are going to equal ICE's for purchase price, and at that point the whole market is going to tip. The only thing slowing down EV sales will be how fast the auto manufacturers can switch over what they produce.

This seems to assume that everyone is buying new cars.

Are people who buy new cars generally concerned about which option is "cheapest"?