I want the clayface, but I have a better chance of winning the lottery and winning a new BMW on the same day then finding this toy anywhere.
My suggestion to you is to order these online for the time being. No one knows at this point when, where, or even if the last of the DCSH figures will show up at retail, so online retailers are where it's at. I have a case coming from Enchanted Toy Chest and it only cost me $2 more to have them shipped to my house than if I had bought them at the store. But if you only want the Clayface from the current wave, then it isn't really cost effective for you to purchase the entire case for just one figure.
I believe that he DCU Classics line will be much easier to find next year than DCSH has been during it's 2 year run. I think Mattel will come out full force next year and will have more shelf space available. Retailers should be on board with DCUC considering it's a brand new line.