In case anyone actually is interested, I speced out some drive pulleys for my Mendel. I am all for printing as many parts as possible, but at the same time their are benefits of using stock materials when I can. Here are some of my reasons.
1.) When price is not significant, accuracy is more important then making the part myself. I think these parts are going to be more accurate then anything I can print right now.
2.) The printed parts are the hardest to get right now. If you are trying to Repstrap these would help a lot.
Anyway here is a link to the pulleys
Drive Timing Belt Pulley
They cost $7.40 each
They have 10 teeth, where as the printed pulleys are only 8. This means you lose a little torque and gain a little speed, but I think the difference is pretty minimal.
Cheers,
Josh