After doing a bunch of research, I think I have settled on what I need for my basic three-axis machine:
Harbor Freight Mill:
Controller from Easy CNC:
NEMA 23 Steppers:
Found some on eBay, I just have to decide on the torque rating I want.
Retrofit kit for NEMA 23 steppers to the HF Mill:
All in all, roughly $1K to get started. This doesn't include registering Mach3, but I am not settled on that yet. Its not the money, but the pride I really have in building it myself.