Until recently, production electric cars cost way too much, even when you figure you're saving most of the cost of gasoline over the lifetime of the car. (A 50-mpg Prius will use about $20k in gas over 200-250k miles; a 20mpg minivan will use about $50k, so I guess you can justify that Tesla if you were going to buy a gas-guzzler and didn't need the space.) Hobbyist electric cars can cost a lot less, if you want to do all the labor to retrofit a very used car with electric motors and batteries, but I don't.
But even now that prices are coming down, the range on the lower-cost cars isn't enough for me. It's fine for going to the grocery store, but my office is 40 miles away, and so is The City, so on the days I'm not telecommuting or want to go into the city for something, I need a guaranteed range of over 100 miles so I'm not worried about having to coast home on electron vapors or stop for half an hour at a charging station if there wasn't one near my destination. Battery range declines as the batteries get older, so that means I'd probably need a 150-mile range when it's new to be sure I can get to work when it's older.
Maybe a couple of years from now it'll make sense to buy an electric car; we'll see how long my wife's car lasts, and whether it's worth getting an electric when we need to replace it. The real cost includes adding an extra electric meter and 240v power to my garage space and the cost of storing the stuff that's currently in my garage, because Silicon Valley real estate is too expensive to actually use a garage for putting cars in...
Unfortunately, most lower-cost electric today talk about monthly lease prices, and hide all the other costs; one of the ones that was advertised on the radio did mention something around $5K up-front and 25 cents a mile if you drive over 10,000 miles a year - the reason I'd be buying an electric car is to make my commuting cheaper, and my gasoline car currently costs about 25 cents a mile (10 cents amortizing the purchase price over 200k miles, 15 cents for gas.)