I am betting the second they announce martial law the lines at gas stations will be 10 miles long.
What does martial law even mean? The local government is still way more functional than building a military form. You could surge the whole DoD into the nation and most citizens wouldnt see a soldier, not to mention that a tremendous amount of the force structure is neither trained for enforcing order AND have important functions in this disaster that dont involve standing at COSTCO with guns (moving supplies, treating the sick, fixing things, building things, etc).
So far the guard has stayed on Title 32 (state authority) because the states know what to do with them. The NGB remembers that Cali was using the guard effectively during the LA riots and that when they were placed under Title 10 (federal) authority, the new federal military command pulled them off of useful work while the Title 10 commander and staff figured out what they could use them for. Not to mention that under Title 32 there are no PCA considerations, under Title 10, PCA does apply.
Further question...if demand is increasing while supply is uncertain, why shouldn't prices go up? Even if it is greed on Wal-Mart's part, it
also fullfilled the market's purposes. It discouraged you from buying the product (you apparently care more about the savings than the cans) so someone who isnt a prepper and really freaking needs it (or thinks they do) can have it. The profit they make off that product when it sells sends signals to the gas can manufacturer to make more cans, and the profit potential will signal people with gas cans and little need for them to put them on ebay and such....increasing supply even without making more cans.