I wasn't able to get me up to gold before doing the quest so I only got 4 reward cards resulting in a small bad mood opening them but after clicking on the first card (far right) and seeing the card starting to shake instead of just open, my mood changed again. And that was not all:
I finally got my 5th Lord Arianthus so I immediately combined them to get my Lord Arianthus up to Lvl 3. Besides, I also got a gold foil Mushroom Seer, both being the most expensive ones in their foil and tier, resulting in a nice +$11 worth in only 4 reward cards.
Good luck guys!