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They're pretty tough to care for and most don't live long in captivity. You want a tall tank, low lighting and a monster chiller. Even with the right conditions people have mixed luck--in the end I suspect some of it comes down to how hardy the individual nautilus is. I--and I think most other TONMOers--would recommend against it.
As a former aquarist, I wouldn't recommend them for the home aquarist. They require cold temperatures, spend most of their time just floating around and don't interact with humans (unless you count eating...). In addition, depending on how they were collected, they could die soon after spending the $$ to bring them to your house.
However, I did have the privilege to see a baby Nautilus right after it hatched. They are adorable!! They look like a minature adult, only about one inch long.
My LFS got 2 in a couple weeks ago. They lost one and the other seems to be doing fine. They do just bob around and "kind of" grab dead fish that come near. No fun at all. They do look cool though. Anemones are more entertaining, even without the clown fish.
They are not extermely difficult to take care of as long as the animal is in good health when you get it, the main problem is related to decompresion causing them to float it can sometimes be cured. The max temp they can survive is ~16C but the colder you can keep them the better. They eat just about anything usually I've feed them dead shrimp, but they also have a habit of eating anything they can get there suckers on such as plastic. Although $150 is a good price its not worth it because they just stick to the side of the tank and every now and then will move to the other side of the tank. The smallest tank size I would put them in is a 120g (48x24x24).