Google does appear to sell some smartphones and tablets at close to cost, for example the Google-branded Nexus 4 phone and Nexus 7 tablet along with the HDTV product Chromecast. The MotoX is not a Google product but instead built by Motorola Mobility, a separately operated company. I believe MM sets it's own pricing and they chose to position this one as higher end.
Noteworthy that Google has yet to have MM build a Google-branded device which probably says there's other companies building a better product than MM at the moment.
Google owns Motorola. end of story.