Board Thread:Game Discussion/@comment-18059447-20140212170809/@comment-42.60.57.118-20140212173551

but its kinda standard already that upgrading costs increase exponentially.

if you upgrade r5s using cards you would see that to level an r5 from level 1-35 takes about 50 cards, but to upgrade the same card from level 78-80 also takes 50 cards.

So i guess the exponential thing just goes crazy with an r6.

but be HAPPY THAT YOU HAVE AN R6 card!!! cos i dont and many others dont either.