To be honest I don't really trust Oracle software. They are usually very expensive and they kinda lock you in their products.
In the case of Commerce Cloud I don't see any pricing information, so I can only presume it's going to cost a lot.
Also a few days ago Oracle bought NetSuite for $9.3 billion. One of their product is SuiteCommerce (http://www.netsuite.com/portal/products/netsuite/suitecommer...)