I have had good luck finding nice canes on e-bay. I have gotten quite a few of them. I really enjoy buying from the artists that have made them. I have even gotten larger lost of them for not much money.
With the larger lots you have to be careful. Some of the canes will be older and misshaped for what ever reason. Most of them I have been able to reshape them and use them all. Every now and then I will get a cane or sheet that is partially cured. On of the canes I have cut and baked into beads which I will wire wrap or use in some other creative way. The partially cure sheet of clay, I will use as “filler” for something larger out of clay or maybe even bead cores if I can recondition it.
I have found that you need to be careful of buying the larger lots. Some of the folks selling them actually have not worked with polymer clay and really know nothing about it. That can either be a good thing or a bad thing, all depending on how you look at it. I have been really lucky so far and have gotten what I would consider fair deals (and even some really good deals!).