The simple answer is I want you to get lots of decks :)
But the truth is there are a lot of factors:
1) Shipping cost just went up again.
2) When you pay $22 for shipping a project creator only sees $20 of that after fees.
3) International shipping not only cost more but it is more work to fill out customs forms.
4) International shipping is a higher risk
I want to send decks global priority so the rewards $30 and up will ship faster and more securely - I am actually undercharging on these but because of the increased deck sells it works out.
So if you are international (especially my Canadian friends) I recommend you find a local friend or two and team up and split the cost with them.
Side note for project creators about international shipping.
If a project barely funds and a good amount of the raised money was for international shipping a creator can be left with not enough money to actually produce the product profitably (example you need $9,000 to print a deck of cards - you set a goal for $13,000 to cover fees and packaging and shipping. if you hit $14,000 as a final amount and $6,000 of that was people buying 1 deck for $12 and then adding $9 for shipping) then the reality is you are about $3000 short of your goal)
The bottom line is I don't want international backers just getting one or two decks - it is just not economical for anyone and I nearly made it so that the first three levels were not open to international backers and then I decided having high priced shipping was better than not giving you the choice.
Disclaimer: I love all my backers equally - I just really don't like filling out customs forms and I undercharged for shipping on most of my levels for the Mazing decks.