Not enough.
Make three tiers of tokens available, Copper Militia Coin, Silver Militia Coin and Gold Militia Coin. Copper drop from lvl 1 battle, Silver from lvl 2-3 and Gold from lvl 4-5. Higher tier can be exchanged for multiple lower tier, but you can not exchange lower tier for higher tier. Make Primal Token available for purchased with Silver, make whatever supposed to drop in lvl 4-5 only purchase-able with Gold.
I'm genius-er than you.
