I just wanted to add to the solutions above (which are great.) When you buy bronze packs to get the achievement, keep just the players( has been said) but fitness card and injury cards are easy to sell to other players. minimum price 150 buy now price 200 and time 1 hour. If you've got e.g. 2 fitness cards and both sell them for 200, you earned back the money you spent on the pack. I'm increasing my club value and earned about 15,000 coins with it until now.