3 people share why they're paying as much as $4 million to live on a cruise ship

• The Storylines MV Narrative luxury cruise ship is poised to set sail in 2025.
• Cabins range from $598,000 for use a few months a year to around $8 million for a penthouse.
• Three buyers, some retired and others who may work from the ship, talk about taking the plunge.

A new luxury cruise ship promises to deliver its residents to ports worldwide in style.