For SCIENCE: I need a bunch of cheap PBT white keycaps

[captain]

I'll be taking a yarn dying class in a few weeks, and thought this would be the perfect opportunity to experiment with professional dyes (not that RIT crap) for use on keycaps.  

Alas, my only PBT keycaps are already colored, and I'm too poor/cheap and not even sure where to get them.  So, I thought I'd put a call out to y'all for any and all WHITE PBT keycaps that you'd like to donate to the experiment.  The more I get before April, the more experiments I can do.  Of course, I'll document the whole thing and post it up here, maybe even write up a wiki, so we don't have more threads like http://geekhack.org/showthread.php?27214-failed-RIT-dye-keycap-experiment-%28

Also, in case I don't get any donations, where are the cheapest bits of white PBT to be found?

[kps]

30¢. Plus shipping, I guess, which could be a problem. I mean, I might have a spare keycap around somewhere myself, but postage from Canada to Neptune is above my station.

[mkawa]

ask melissa for a material sample. basically you want a white swatch

[kaiserreich]

SP has them at $1 each if you want a lot more.