You know the Dutch turn the penny not only twice but 200 times. I've experienced that by visiting a friend and having to use tea bags twice by freezing at 60 degrees (16°C) inside

. Still, here the rules are different because lover VAT in Germany of 16 % to I guess 20 %. Will not save much but on a diamond Love it *makes* a difference.
As for Switzerland it depends on the exchange rate. As I just see it's 7-8 % cheaper due to their 9 % or so VAT. However you need to get there first and consider the 2 % exchange rate loss. I guess legally you need to pay 20 % tax out of Switzerland, not so in Germany. Plus beware of buying anything else: Pricewise you'll feel like being in NYC; a bus ticket is USD 5 or a sandwich sets you back $10.
Here we go for the diamond small JUC:
NL 4550 EUR
DE 4350 EUR
CH 4120 EUR
US 3650 EUR plus tax (in NY EUR 3970); wish to live in OR
SG 4250 EUR
HK 3630 EUR (no sales tax)
JP 4190 EUR