I have put together one for myself and one for my wife. The hardest part is keeping the weight down. You would be amazed how heavy it starts to get once you get everything you think you might need. I did an excel spreadsheet, which tracks the cost and weight (down to the gram, since I am obsessive) of everything in the bag. Most of the small items are just a buck or two and not a big deal (lighter, baby wipes, pocket knife, extra clothes, etc, etc) but I do have some expensive items in there such as a portable solar setup from goal zero (to charge phone, ipad, etc) and a handgun. If I remember right, the total cost came out to around $1200, but without the two previously mentioned items, it would have been barely half that. You also want to make sure you get a good comfortable pack, you might have to wear it for many miles or days in an emergency. After you get it together, take it on some day hikes to test it out. I was able to get mine down to about 26 pounds, but even that feels heavy after a couple hours.
