Depending on the size of the machine you're building, your best option may be to wait until you can save more money. You get what you pay for.
You might want to look at HobbyCNC | CNC for the desktop machinist and hobbyist., though.
Add 3 200 oz motors and you're right around $150.
1.8DEG. 3.6V SIZE 23 STEPMOTOR-MPJA, Inc.