Wow. I remember seeing like last week the tickets were like $250,000. Apparently it's completely experimental, isn't actually' regulated/approved' by any official body. If it's on the ocean floor it's around 12,000 feet which like 10,000 feet further than any submersible has ever successfully had people rescued from in the past.
96 hours of air when they left Sunday morning would mean oxygen is only ok until about Thursday morning... but that assumes there is no oxygen leak and it's basically all electronics that failed (and the system in replace can scrub the air/replenish oxygen from the supply with an electronics failure).