Ah, if it's for someone else (presumably a first mic?) then that changes things - I assumed it was for someone with experience of mics already and wanting another mic or an upgrade. For a beginner recording and getting something okay down is a good result, so gear snobbery need not apply.
I think the Se X1 is a viable alternative to the MXL, but doesn't include a shockmount (which is nearly criminal), otherwise I would reccoment it wholeheartedly.
In the UK both are ~£80, the Samson is ~£45 which is quite a sizable difference. I think that if it's a first mic, any of them are good choices but I think that the X1 or the MXL will probably last your brother for a while longer if he keeps recording. If your brother wants to get more into it and learns what he likes and doesnt like about mics then he can upgrade/replace later on.