@Bev81 from France;
1. read my OP carefully.
2. New FZ1000 is @526 USD as below from Amazon JP
3. Amazon Japan is not the lowest price in Japan, and Japan is not the best price in Asian. I think you know that.
4. I assume that you know how to order cameras from
overseas, as well with international warranty.
5. Repeat my #1.
6. I think you know how to use “Currency Calculator” to covert JPY to your currency in your pocket.
Any questions (?) as I see you have LOT of “?????????????????????” in your post.
BTW: Check the RX10 price by yourself, would you?
You can do it.

Started out doing photography at the age of 6 using an uncle's old 1940 kodak brownie box camera. At 15 years of age, I decided to buy my very own 1975 Praktica SLR camera. I now shoot with a Nikon D850. I do unpaid TFP and commercial paid work.