It would be interesting to fine-tune and rank the list by probable value AND size / ease of storage. (i.e. the smallest, most probably valuable items go to the top of the list). Realistically, many people won't have space to store a reasonable supply of personal preps AND sufficient goods to barter, so going for the small stuff will help in this regard.
As NR says, this is already starting to happen in parts of Europe:
http://www.guardian.co.uk/world/2013/jan...rty-crisis
Find a resilient place and way to live, then sit back and watch a momentous period in history unfold.