Yes I can definitely see a lot problems that can emerge from it, but making it illegal I think will cause more problems than it solves, and fundamentally goes against the principles of a free society. I do think desperate people are capable of providing informed consent. We shouldn't take their agency away from them (and if we do, we should do it officially, through the state becoming their ward).
Also, it's often the case that making it illegal just pushes it further underground, where people have fewer protections.