EV-electric vehicle runs on electric power solely
Hybrid- internal combustion engine + electric motor
Theoretically you can build an EV for as low as 500-1000$ assuming you've got some skills and plenty of time on your hands. As for hybrids I can't really tell you but it will definitely be more costly.
Another aspect regarding building an EV would be the donor vehicle, which should be as lightweight/aerodynamic/low rolling resistant as possible. In my opinion a Chevrolet lumina is on the heavy side, I think you should look at other options to start with.
Anyway, I'm really a newbie in all these, haven't done any of it myself, but on this site there's plenty or real experts who built some amazing vehicles.
I would say start here :
A $672 electric car, built by two DIYers | Hypermiling, Fuel Economy, and EcoModding News - EcoModder.com
Top 10 electric car conversion links | Hypermiling, Fuel Economy, and EcoModding News - EcoModder.com