Should I buy a MacBook Pro in Japan and how to handle customs when returning to Europe?

Hey everyone, I'm currently on holiday in Japan and seriously thinking about buying a MacBook Pro M5 Pro here. My 2019 MacBook Pro 13" has been overheating constantly and the RAM just can't keep up anymore, so it's time to move on. The math seems to make sense. As a tourist I get 10% off at the Apple Store tax-free, and from what I can tell Japan is one of the cheapest places in the world to buy one. If I declare it at customs on the way back and pay the full VAT I'd still save around €300 compa