In an emergency doors jam, locks seize up, or you cant find the key, things get in the way, sometime things just richly deserve a good beating. A well made pry bar will see you through these sorts of situations.
A top-of-the-line Halligan would be ideal but the really good ones are pretty large, are difficult to store with the spike sticking out, and they run in excess of $200 each.
My preference for emergency kits is a flat bar. For equal size and capacity they are usually a bit lighter and often cheaper than a bar made from hexagonal steel section. Also the wider blades opens up options for prying laterally, scraping, using it as a hoe to shift mixed gravel and debris. The thinner blades, which I usually grind down to a fine edge, work better on tight joints without having to resort to hammering them in.
For $13 you get a nice brand name unit that is sure to be reliable:
http://www.northerntool.com/shop/tools/p...la=&cm_ite=For $6 you get one with less peddigree:
http://www.northerntool.com/shop/tools/p...la=&cm_ite=For $3 you get a generic:
http://www.northerntool.com/shop/tools/p...la=&cm_ite=Note that all three tools may indeed be made in the same factory from the same steel as the Vaughan Super Bar. The Vaughan just getting a little more finishing, a paint job, and a label. No guarantee that that is true but the general trend is that good quality tool steel and the cost of heat treatment has dropped in price so much it really doesn't make sense for anyone to make a bar that can't meet minimal standards for quality and usability.
Just to be sure if I was going to buy a quantity of the cheapest unit, perhaps for an organization, I would get a sample and put it through its paces to make sure I was getting something functional.