Oracle is out with a version of this called Commerce Cloud (https://cloud.oracle.com/commerce-cloud). It is based on their existing market leading ATG/Oracle commerce product.
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...)
From https://cloud.oracle.com/en_US/commerce-cloud?tabID=14306513...
Usage Model - Tiered-pricing structure based on annual storefront page views Revenue Share Model - Percentage of GMV