I will be re-releasing all four individual volumes through Amazon's CreateSpace service sometime after the Kickstarter campaign is over. However, the epilogue and prequel comics will be exclusive to the omnibus.
That is the number I got when I put the weight+size of the book into USPS.com's price estimator and choosing a destination outside the US, with a few dollars added for the cost of packing material and fulfillment.
Don't see the answer to your question? Ask the project creator directly.