CJM Associates via Amazon offers Prime members the RoomMates Disney's Frozen Peel and Stick Wall Decals 36-Count Pack, model no. RMK2361SCS, for $8.75 with free shipping. (Non-members can spend over $35 for free shipping; otherwise, it adds $6.94.) That's a buck under our October mention and the lowest total in-stock price we could find now by $2, outside of other Amazon sellers and the mention below. They apply to any smooth surface.
A close price: Lilmead via eBay offers it for $8.94 with free shipping, but stock is limited.