Similar to the theme of inventors, vampires, ect. I would be happy to spend crystals on a weekly rotation of the 5 core colors (plus 1 of colorless) with the usual guaranteed rare.
This will help raise my mastery of lacking colors and could be an option to reduce my chance of duplicate rares for colors that I feel I am not lacking in.
It used to be 10000 runes, x5 pack, and 600 crystals for $24.99 USD. So as a thanks for playing, for $5 more I get two less packs. Not even enough hickory nuts to throw in some Unobtainium. Thanks I guess…