This is a REVISED and UPDATED for 2018 resource.
There is a lot to think about during any major situation. One thing that it is easy to predict is that if the supply chain gets shaken, it can mean that some things might quickly disappear.
One of the main things to remember about prepping is that you need to have the items you absolutely need already on hand as much as possible. Luxury items and non necessities can make a situation better but it is important to prioritize your prepping so that you can make the most of what resources you have.
A list of items likely to disappear during a SHTF scenario is also a good list to get ideas about what extras you can put back for trading or selling. A $10 investment now might go a lot further later on. Considering having some extras besides what your family needs to be an investment in the future.