That makes some sense to me, but if the goal is to always have a nice car, doesn't it makes much more sense to lease? The monthly payments will be a few hundred bucks less and you can upgrade every 2-3 years. And from what I understand, leasing agents like to give incentives after your first lease to keep you in the cycle.
Personally, if I were aiming for the most economical option, I'd lease a Nissan Leaf for ~$300/mo.