Everything john said is 100% correct. However, since you said nothing about speed, and DID say you needed to save money, why not scavenge or salvage motors? There is a list of motors and where you can find them at:
techref.massmind.org/techref/io/stepper/linistep/motors.htm
I typically advise against trusting anything that is direct shipped from China. It's better if a US vendor is standing behind the product.