Here is how I would do the blades. You need 3 so you can balance the tension. I did some super quick sourcing and I could get the raw material for each individual blade for 25 cents. (You will need to make a stamp to cut out the slots on the end and you will have to form the ends. We could probably get a spring shop to make these for us.) With 608 bearings costing 25 cents this is not an immediately a winner.
Options: You could stick with the strings like I did on Wally. You could also use some other type of film or fabric. Nylon strapping comes to mind. That would take the cost down to pennies per strap. Could we print the straps in nylon?
Notes: A well tensioned setup like I have in the rendering should have very little axial play and would therefore be a good bearing replacement. I think I will play with the nylon straps (printed or woven) for the VRDLCJ. (Variable Ratio Double Lamina Compliant Joint) Of course, that will be months from now. I hope someone else can test this first.
My wife and I kept on trying to pronounce VRDLCJ. We kept saying Virgil. I propose we call it a Virgil Joint.
@A2: I have never heard about Rolamite bearings. Thanks so much for bringing them to my attention.