In a nutshell: no.

You're not helped by the current weak pound in that respect.

I'm totally guessing here, but I imagine the shape of the DVD package probably influences the price. In the UK, the postage is now determined by size of envelope (though obviously weight is still a factor).

Have you thought of simply offering the same package but just in a see-through plastic sleeve as a separate option? They cost almost nothing, and you could mention something on your website about that being an option for overseas sales. Less of a carbon footprint, too. Not sure if your 60-page booklet would still fit in, though.

A lot of record companies send out review copies in those plastic sleeves, or paper ones, and I don't think any less of the music inside when I receive one.