Rimowa in Japan

Hi all. I'm going to Japan and South Korea for my honeymoon mid April. I'm interested in purchasing a silver cabin carry on.

Would you recommend the cabin or cabin plus? I don't want to have issues with not being able to bring the cabin plus as a carry on so that would be my only hesitancy. I live in the States for reference.

How much of a price difference can I expect in Japan if I buy directly from Rimowa or other authorized retailers? Also, how likely is it to purchase one second hand? And any idea what the going rate is on that?