Is it ethical to purchase someone else's work and submit an edited version for assignments?
If he would cite it and then get the marks only for the added value of his own work, then it would be ethical.
If he submits it to get credit for it all, this is highly unethical, in fact in my personal opinion even worse than plagiarism, as it is far harder to prove the misconduct and demonstrates an elevated level of (academia-level) criminal energy beyond the usual misdeeds.