Unfortunately Nate gave a pretty compelling argument for not adding any new skins in the near future during the last town hall.
You can buy potions with SPS if you make a side trip through credits, but I think that's all going to the DAO, not burned. I don't think they're willing to burn any SPS until we're able to vote on it.
Personally I see ranked rewards canceling out any increases in SPS price until RW arrives, but I hope I'm wrong.