The newest Mario and Donkey Kong title is way cheaper than the last one.
A new promotion will be launching in Japan at the end of the month that rewards amiibo buying with a completely new game.
Beginning on the 28th of January, purchasing an amiibo from select Japanese retailers will qualify you to receive download codes for the brand new "Mini Mario & Friends Amiibo Challenge". Should the game come out in English, it will be a part of the Mario and Donkey Kong series.
According to the Nintendo Topics (Japanese link) article, the game will be distributed for free at a later date. More details on the game's amiibo functions, and any news of a Western release, will come at a later date.