I got 5 Rimowa pieces in Germany last month. As someone said, a long layover can be a great savings opportunity, as my total cost was close to $2,500 less than the US.
However, there are several things to keep in mind here: the stock is absurdly unpredictable. I got incredibly lucky as they just had a delivery that morning and bags were in stock.
The sales lady told me that literally any other day in the past several months they would have sent me home with one, maybe two bags at the most. They have lines of people waiting.
Second, they have a limit of bags per person. I was there with my wife, so we got two bags each, and even that was a Manager's exception as they sell one bag per person per day.
But wait, there's more! German Customs like to inspect your bags to stamp your VAT forms. I screwed that up because I checked bags in (thanks, unhelpful airline employee), so no VAT refund for me.
Last but not least, it is impossible to contact the Rimowa store in Germany ahead of time so you are shooting in the dark here. I emailed them ahead and called over 100 times - zero response.
Yeah, good luck!