So you are gluing in the cart holder in the box.
There also seems to be place for a booklet.
I already got my new "blank carts" for my next homebrew game. To keep cost down I would like to print out the box, the insert and the users manual good quality but without folding or assembling them. And send it in an A4 envelope together with the cart. This would nicely be delivered as an ordinary letter and not as a maxiletter.
The magic measures are:
Example Finland -> USA
50g, thickness below 2cm = 1,80€
100g, thickness below 2cm = 2,60€
50g, thickness above 2cm = 10€
250g, thickness above 2cm = still 10€
How do you feel about having to fold the box by yourself?
On a related topic. I would love to get some help with designing the box, cart label and manual for a small game that I am working on. It may be ready in a month or so.