should I buy a 50mm 1.2 in shanghai or tokyo?

I live in Shanghai and the local camera shops sell the 50mm 1.2 imported from Hong Kong (with HK waranty) for about US $1,350. that seems to be a fairly good deal based on a quick comparison to b&h ($1,619.00). I will assume these lenses are legit and new for now.

next week, I will be flying to tokyo. if you happen to have experience with local shops there, do you think prices are comparable? I only know to go to akihabra and would appreciate specific well-sorted shops (also for accessories, I have a long list of quite specific stuff I need). or are prices in japan currently higher?

thank you :-)