We got a 2014 Prius C Two for slightly more than $20,000 with taxes, tags, and such (MSRP was $18,555 I think). We did finance this one at 0% for 36 months, but we will invariably pay it off early, and then we'll drive it into the ground.
Don't ever pay off 0% financing early if you are keeping the car.
It's free money.
Debt is only bad if it is used improperly. If debt helps you make money it is good. If you borrow simply to buy things you can't afford, it is bad.
Interest free debt is the best kind. A dollar today is worth more than a dollar tomorrow. If you have the case to pay off the interest free debt, put it instead into a mutual fund or something and don't touch it. You'll be richer when the debt is paid off than it you pay it off early and don't save the payment amount for the life of the loan (and probably even if you do save it).