The Echo is OK if you're satisfied driving something that offers roughly the same crash protection as a tin can with airbags.
What happens after 7-8 years when batteries go dead?
It's another $4,000, plus disposal of the old batteries.
You own a 7 year old car that needs batteries plus repairs, and what economic decision would you make?
Sink another $4-5000 or more, depending on additional repairs into your old car?
Your resale value of course is $5,000 less (buyer needs to get new batteries) than what a gasoline vehicle of the same age would fetch.