All,
Discovered an unusual source for clear bases. I was killing time in my local CVS, while my wife shopped for birthday cards. I noticed packs of Scotch Restickable Dots. These are clear, 22.2 mm circles meant to be used to stick things to walls. They are $2.49 per pack of 18 at CVS. I decided to grab a pack to see how they work. Well, they are perfect! I stuck two together, to make the base stiffer. That works out to .27 cents each!