Most patients in the Phase II and III trials received two rounds of infusions. The first round of infusions lasted 5 days and the second (12 months after the first) lasted 3. I don't know how patients many (If any) were hospitalized in order to receive the treatment, but I think that the majority of participants received the infusions on an outpatient basis- turning up in the morning and going home in the afternoon. Follow up involves monthly bloodwork to check for side effects (particularly ITP and thyroid problems). If you receive the treatment off-label you'll have to discuss with your doctor how he plans to give you the drug and do the follow-up, but sticking to the trial protocol is probably the wise thing to do.
We paid £9,000 for the first round of infusions in a private hospital in London, and the quote for the second round is £6,000 if I remember well. At the moment the drug is licenced for leukemia only, I believe when it is licenced for MS it will also be priced in line with other MS treatments, that is probably more expensive than it is now.