I think most of us were a bit underwhelmed with top ranking players rewards (10k for 10% and 100k for 2% with transmute crystals).
While I think these are cool bonus, they certainly don’t make grinding the game to get top rank really interesting as we can get gold everywhere and much more efficiently.
One thing that could be done, is adding an additional aesthetic reward for top players that makes one or more of their cards have a little shine effect and, maybe, even a little animation of the picture when hovering the cursor on them.
It wouldn’t break the game, affect gameplay or destroy the economy, but it would be funny to play against a random player and finding out that half their cards are foiled and that they are a veteran at the game or be in the reversed position of showing off foil cards.