Omega2 Kickstarter backers do need to pay for shipping fees.
This was stated on the Kickstarter campaign FAQs and the campaign page itself:
For full details, please see the Omega2 Kickstarter campaign page: https://www.kickstarter.com/projects/onion/omega2-5-iot-computer-with-wi-fi-powered-by-linux
Thank you for your understanding.