no way to earn them still
From what i remember you can get them on few ways:
- from few events like current "Courtesy Card" (rare random reward)
- from Castle Chest V and VI (rare random reward)
- if i remember correctly, you can get them from Labyrinth Goblin Chest (rare random reward)
- You can also buy in warehouse, but cost is high (but Rusty already said it)
So it is not like it is impossible to earn them which means your statement is wrong. It is not easy to get them, but possible for all. No cash involved.