MREs are readily available in commercial form from a number of companies. Sopacko and other government contractors offer commercial versions for sale, check the Cheaper Than Dirt catalog, Sportsmans Guide, et al.
However... Commissaries on military bases are authorized to sell them to anyone with shopping privledges - active duty, retirees, reserves, dependents. The ones sold thus are "real" government issue ones. Cost comes out to be slightly more than the commercial ones, but not too badly because you avoid shipping charges.
Thus if you, or someone you know, has comm. shopping privledges, they can contact the store manager and make sure that stock is available, and arrange to purchase however many are desired.