Cheapest place to get Nema 17 stepper motor?

Hi,
I am planning on building a 3d printer on a tight budget, and so since I need 5 stepper motors, $12 usd for 1 nema 17 on ebay is more than I would be willing to spend. So I was wondering if anyone knows of a place where I can get nema 17 steppers at a low cost or second hand?
Or perhaps is there a cheaper alternative to the nema 17?

Thanks