Just preordered mine from here, price seems reasonable. It also lists a release date of 1/1 which is earlier than I expected… anyone have confirmation on that?
From sunyshore they are $40.00 USD each + shipping link
From hoshiiya they are $45.00 USD each + shipping link
My suggestion for these boxes is choose a service that ships the cheapest for you
Sometimes sunyshore charges a bit higher on shipping, but maybe ebay has a rate that is cheaper to your specific location. Best of luck!
The ebay link @areestee posted actually works out a fair bit cheaper than either of those links after shipping, for the UK that is, either $40 per box with $37.50 shipping for the pair or just straight $45 each wth free ship.