I just realized that there is nothing in the game that you can purchase and then re-sell later without taking a massive loss. The ramification being that accumulating wealth is limited. Obviously by design.
Explanation: You can't go and purchase valueble stuff with the idea of cashing in later when you need the gold. If you want to stock-pile wealth you can only accumulate valueble treasure from quests and cash-in as needed.
If you garden, you can buy gardening spells. This is a great way to lose a massive amount of gold. The only draw back is that you can only do this one time.
Actually I got the gold warning when was hitting close to 300,000 gold. I am reading other thread post of higher than that, so I am not sure which person to believe.
However I went ahead just wasted all of it on 250 sun stones over time. Now I am getting into crafting but it doesn't solve the problem since, the only thing I am forced to waste gold on is, learning all the plant spells, crafting, learning low level useless myth recipe gear, and crafting quest.
I am not sure if I will get into pet breeding, the game is starting to become a daily grind but who knows.
I know for sure I would never waste any gold on those silly houses or terrible taste in mounts, maybe in the future they will have more appealing housing and mounts I would waste gold on but for now, getting tired of the warnings at 300,000. It should be like 1 million cap or something.