I had the same feeling about the rewards cards... There is a serious glut and it is damaging the economy. I made a suggestion of a card burn option to try and break down the sell walls at 0.02 usd. The post is around 5 days old, I won't link drop unless you ask for it.
I'm glad someone else found it hard to rank up... I was stuck in silver for ages and only managed to break into gold on the last day... But then I only play the daily quests and nothing more...