So... I never bought them. Kind of wish I had. Looking to buy any old cash shop item that unlocks a challenger; please name your price. I have both CSC and sP. Favoring stuff at the "Very Hard" level and below, but I will purchase the others as well.

They should be available again in the Cash Shop during the Black Friday sale in November if you want to wait and save some sP/CSC! However, the challengers don't get discounted and will still be 250 CSC apiece.