An undergraduate said they may hire a freelancer to do their work for them. What should I do? I, a graduate student, have started tutoring undergraduates in computer science at my university to help make ends meet. One student who inquired about my services turned me down upon hearing my rates and remarked (in writing) that they might as well just buy solutions to their projects on a particular freelancing website for that price, as their friends do.

Should I tell the professor about this student, in case he wants to review their submissions more closely? I don't have any proof that they have already cheated, but to me their exact words (which to protect my anonymity, I have chosen not to publish) and phrasing suggest strongly that they are likely to. In this question, the OP appears to have evidence to suggest that cheating has taken place already, which seems more clear-cut.
[The student] remarked (in writing) that they might as well just buy solutions to their projects on a particular freelancing website for that price, as their friends do.


That does not sound to me like "admitting" that they "would" cheat. If I said to a prospective financial advisor, "your rates are so high I may as well just declare bankruptcy now", that does not mean that I am going to declare bankruptcy, it is merely a way to express that the advisor's services do not seem cost-effective.

Given this, I would do nothing -- you offered legitimate tutoring services and the student declined your offer. You have no compelling reason to suspect that the student will actually cheat.