Hi Kim,
There definitely will be no break even point on my project. The conversion part of my project totals about $7000, batteries included. Building a car out of the tub and few pieces I had to start with is costing me much more than the conversion.
Building an electric car has been a dream of mine since I was a teenager in the 70s reading Popular Mechanics and Popular Science, during the last big gas crisis.
I got the pieces of the Sprite in the early 80s in exchange for some work I did on a friend's car. I tried to start the project many times over the years but school, family, work, money, etc, kept it on the back burner. I finally got the car out of storage, and into the garage about a year ago.
The batteries should be good for about 1000 full charge cycles. I do know if they can be "rebuilt" by an average user, but they are definitely fully recyclable.