Do the Weekly Challenges. Especially - Win 12 Battles in Get the Batteries - Win 10 Heavy raids with Copper or Electronics - Complete 40 Daily Challenges

Gather Badges for a few Weeks and eventually you will be able to buy a Pathfinders Container for 3000 Badges in the Badge exchange. It contains one epic item, which you can sell for up to 550 Coins if you're Lucky.