As I speculated a few weeks back, there is something driving Minecraft demand. Skin Packs, for example, are selling for 2 x RRP even though they are £10.99 at Lego. Crazy.
I think there are core fans out there, who collect and trade sets. Also a lot of You tubers who recreate their online worlds. Most retailers sold out of MInecraft in the Xmas run up and many sets have unique pieces. 2017 retirees will be gold but 2018 sets will be much more hoarded as a result.
That said, I'm no MInecraft expert and would love to know what MInecrafters (not AFOLS) want in these sets.