I looked around the spiral, and I can not find a place to sell the Poly cards. Its a shame that they will be deleted with no benefit to my wizard cause this means every time he got a treasure card of polymorph it was just a waste of effort and no benefit to my wizard. He might as well have gotten nothing because he will delete them and get nothing. Least open them for trade so those wanting to use them can least be given them. If a vendor sells the cards Or a teacher gives them out as school items they should least buy them back. The cards have cluttered up my deck to the point I have to move them. If I had wanted to turn into a life I would have made a life instead of the one turning. The only card I enjoy is the fire Draconian and it is no longer in the game i believe. I still have a few of them but they will be only ones I keep. Shame there is no selling them. Perhaps this is something the game can improve on and give benefit to many as I believe I am not the only player with this problem.
These cards are no trade due to the abuse of them by people giving them to lower levels. I do believe there should be a way to sell them along with the gardening cards.
Some of my polymorph cards i used crafting different furniture in Celestia. Another way I have gotten rid of these cards is by using them when farming lower level bosses.