the way it works here with Kickstarter, as I understand it,is..
you take your original pledge, and then add to it to bring it up to what it would be if you bid for all three
then when we send the survey out at the end,
you let us know what the extra money was for
and we send you all the stuff.
Kickstarter lets you pledge more than the minimum price for any reward,
and that way someone who might want to give a little extra can
or someone overseas can bump it up to compensate for
the overseas postage or whatever.
Don't see the answer to your question? Ask the project creator directly.