Source for stepped pulleys

[DavidR8]

I've seen a few freebies and lots under $100, compare that to how much money and time you will spend on pulleys plus it would be more compact.
Edit - I saw a treadmil on usedvic for $80

My challenge is that I have no idea what I'm looking for. I read posts about this kind of motor vs that kind, this controller over that and my mind goes to mush.
I guess I need to do some proper research...