Rimowa is infamously expensive in all parts of Asia. It's also quite expensive here in the US. The cheapest place to buy (in my experience) has been in Germany. I know there's a store in Munich (not sure where else), which would probably be best. If that's not realistic, there's a department store called KaDeWe (www.kadewe.de/en) in Berlin where you can order by email and have them ship to you.

I would definitely suggest not buying in NY, HK or Singapore.