Hi Shanqi,
I'm going to Tokyo in 3weeks time. To be frank, Yen has dropped quite abit (little bit) coz i frequent there every 6months (or 3x a year) depends.
You can ask your friends to consolidate your purchase and then get a discount card from Burberry for your next purchase. Split your purchase.
Otherwise can always buy online in Singapore and spend your yen on food coz ultimately Blue Label is made in China only original Burberry (UK) is made in Japan.