I bought something really cheap, as in literally cheap. It's because I purchased i71 Cheap Congas though its price is not the cheapest among the Common cards I bought. It gave me only 5 Luck, nothing more, nothing less.
My ranking dropped a bit again currently at #1728. Anyway, I just noticed the number of total active players during the last 7 days. A new update I think. Since there 7225 active players, it seems my ranking isn't bad.
I'm closer now to Level 55 too, and excited to do a new mission that will bring me to music stardom.