Regarding the pricing of Delrin and other plastics:
If you live in any sort of big city, check to see if you have an industrial plastic supply company nearby. Tap Plastics, RidOut, etc. They always have a scraps/cut-offs/rems bin that is pennies on the dollar, and usually sold by weight. For the size of the chunks outback97 used, I doubt I would have paid more than $4.00 out the door.
That's good to know, thanks Herbie. McMaster-Carr is so convenient as I get stuff from them next day without driving anywhere, but I'll take a closer look at other options next time I need some plastic for a project. Unfortunately most industrial supply places are nearly an hour roundrip from me and open only M-F, so it's hard to take advantage of them.