system
Given the following post, respond as if you're commenting on Reddit:
human
[Dragon Ball Z] Why does Frieza sell planets after wiping out their residents? What does he need money for?

He was the most powerful being in the universe (as far as he knew). Surely if he wanted anything, he could just take it and kill whoever tried to stop him, right? What’s the point in buying or selling anything fairly?
gpt
Professional pride. Frieza is nothing if not proud of himself and his accomplishments. Also, running an empire requires a lot of capital.

Besides, if he simply ran around killing whoever and whatever for minor reasons like money, he would've drawn Beerus' unfavorable opinion rather than just his disinterest.