Erik did not keep this knowledge to himself simply out of greed. He understood that it would also be of great use to the kingdom. However, he had paid for his own shop, bought a house for himself and Akarui, and was even funding his experiments out of his own pocket.
Reinvesting most of his profits into his experiments, for now, he was making enough from potions alone. But he was prevented from attempting to make higher Tiered potions. Luckily, Erik was not in such a great rush as his friends. He didn't mind learning all he could before climbing the Tier ladder.
Sadly, as a result he didn't have much saved for rainy days. And form past experiences Erik understood that having capital saved for such days was pretty important.
Hope you enjoyed the chapter, :)