"In 1989, Congress directed the Defense Department to conduct a study of the separate military commissary systems. The ensuing report by the Jones Commission (headed by Army Lt. Gen. Donald E. Jones) recommended consolidating the service systems into one agency to improve service and save money. The Defense Commissary Agency (DeCA) was established May 15, 1990, by a memorandum from the deputy secretary of defense."
And:
"Commissaries still sell products at cost as they have since 1825. Today’s customers also pay a 5-percent surcharge, mandated by Congress. The surcharge pays for new stores, as well as renovations of existing facilities. Patrons thus help pay for their commissaries twice - once as taxpayers and once through the surcharge."
I go there for the occasional haircut, adult beverages and stogies. If I really need a specfic item, chances are pretty close to 100% it won't be there.