Decided to go to Ginza Wako today, ended up purchasing a Herno jacket (this one: https://guji-online.com/fs/guji/14031004132). Normally goes for around 150,000 JPY, so already a ~30% discount from the exchange rate. Then, they offered an additional 30% discount (unclear why??) and then duty free took off another 10% so final cost was ~90,000 JPY = 600 USD, a 60% discount from the "normal" price.