I have devils write all my wishes for me. I tend to hand my DM two to three pages of "this is what I mean, do not screw me over." Their standard fee is 15,000 GP
I'll cast the Wish/Miracle, I just make sure I'm getting what I want out of it.
GPT-4 is getting scarily better at avoiding hallucinations. I recently told it to hypothetically worldbuild based on a culture that I specified and it scarily has the niche knowledge regarding the culture. Whereas GPT-3.5 only uses general information to worldbuild.
But I heard human souls are more volatile than weak cryptocurrencies, one day they can be worth millions and at the end of the day they might be worth almost nothing (they'll never be completely worthless but they sure get close), so it's a rather risky investment.