Pyramid Island
We start with 200 coins. We can collect 600 coins every 8 hours (for collecting times check this = 5600 coins in total. We can get 600 more coins from the coin quest. Then we have 6200 coins. But we need 12000 coins to finish the path to get Radiant Dragon #876. So we have to buy coins if we want to get it. But there are some nice rewards on the path. So it is worth to collect and just move.

There are also Radiant Orbs. Hopefully we can get at least over 80 and then we can use Joker Orbs or trade with people who already have Radiant.