Eh, I have done way less ethically challenging things in my life and already consider it. Honestly, I can't imagine the amount of exploiting you'd have to do to accumulate a billion dollars.

You are talking like 23,000 years of labor at median wage in the US to have a billion dollars. If you are Elon Musk, you are talking like 10 million years.

If you are okay walking through the world like that, I think you have some problems.