Long story short: I am in Japan and I have found a beautiful used Octatrack MK1 - in very good conditions- at a very reasonable price (around 600 euros). I want to buy it in a Tax Free shop (which means registering the purchase on my visa). My question is if, when I get back by plane (I plan to bring the OT in the backpack with me), will I be requested to pay import duties?
If so, will it be better to ask to pay the full price with taxes (10%, will still be a very good bargain I think) so the transaction does not get registered and I can bring the instrument as my personal item?
If you have experience of Japan custom rules and you have suggestions you are really welcome.