hey! wanted to hop in and say why this is:
we originally were going to add trade rerolls for an increasing cost, so 5/10/15/35 gems for each rarity (common/rare/epic/legendary).
but we decided that we will most likely change it to a flat 10 Gems per rarity instead.
we are still fiddling with various numbers so other reward numbers (such as gold and fame etc) in the video can and will change in the final version!