I have gotten a collection player. Machado to be exact. He took 18k gold. From my experience it is almost impossible to get gold from the cards for free. You must spend at least 5k gold before you start getting them. Out of the 18k gold I spent on machado, I got 1k from getting gold cards.
I spent about 18k for machado. If you want to spend less I suggest you wait until the last few days so you have already collected a few trophies from login. He is my only prime player. 370 avg and homers every 5 at bats