to leaf or not to leaf?

Brand new to forum and very interested in do's/don'ts of purchasing a new or used Nisan Leaf. My state of WA gives up to $1,600 rebate/used, up to $3,500 new plus the fed gives up to another $7,500. We own a 2005 Prius which has served us well up until the past two years when $2000 worth of...