HD Report has a run down on where to buy and which store has what special package, more at the link.
Best Buy has an exclusive Noah edition in SteelBook packaging that comes with a Blu-ray Disc, DVD, and Digital Copy via both UltraViolet and iTunes. The edition, with a list price of $26.99, only appears to be exclusive in its packaging.
Target has an exclusive Blu-ray edition in wood packaging (which is quite fitting considering the topic of the film). The edition from Target includes a Blu-ray, DVD, Digital Copy (UltraViolet/iTunes) and Bonus Blu-ray Disc. The edition has a list-price of $22.99.
And, a Walmart exclusive with Blu-ray, DVD, and Digital Copy includes a 12-track music CD with music inspired by the film from top Christian artists such as For King & Country, Chris August, and Jason Castro. MSRP of the edition is $39.99.