With japanese sets I get a few boxes in just to open them up because that’s part of the fun! Also the fact they are so cheap means you can open up a few boxes for not really that much money!
Would it be cheaper to just buy the set in singles afterwards? - Yes.
Do you value the pleasure of anticipation? If you enjoy a sense of gambling, not knowing what you are going to get, and getting excited about pulling that rare card then you should buy some boxes.
Hopefully that gives you an idea of EMS shipping charges based off of number of boxes ordered. Do not ship registered SAL/unregistered SAL unless you want your cards to slowly descend into the Postal Service’s ISC New York black hole of hell.
Would love for a big buyer to comment on theirs. I have an order of 14 boxes and 4 of the smaller BREAK packs on order for September. Will be interesting to find out how much shipping will be, but I am betting on less than 600¥ per item. I think you can accurately calculate it yourself if you know the weight. Each booster box is roughly 280 grams from memory. I would assume that the BREAK packs would weigh under 140 grams each.
Edit:
Just looked up the price for 5kg (likely the beacket my order will fall into) and it equates to 8200¥ for EMS and 5000¥ for SAL. That gives pricing of roughly 515¥ and 313¥ respectively per box.
I’d rather pay for the security and priority that EMS gives me.