I paid my rent and living expenses when pursuing my Masters degree by writing papers for services that helped undergrads cheat on class/term papers.

I don't regret it at all. It helped me become a faster, more efficient author, and in my experience, the sort of student that would pay someone else to buy a paper will end up failing out one way or another regardless. I knew people that paid for papers in undergrand, and most either flunked out, or barely graduated and ended up worse off than our other classmates in terms of job/grad school prospects.