I was going to spend about a grand on a cheap bike and some batteries and a good hub motor for the front wheel.
Then, the more research I did, the more I realized what a pain in the butt it would be, dealing with burned out motors, batteries, charging, weight, etc.
I came to the conclusion that for a thousand dollars I could get a pretty darn nice bicycle. So I did. I spent 700 on a nice Trek Soho and then purchased some accessories like a helmet, riding outfits, lights, a rack, and a few more things.
I ride four miles each way to work, with some hills, and am loving it.
No electricity, no batteries, no worries, and my butt is getting firmer. My wife has noticed a difference in my body.
It's a no brainer.