I know you have probably all seen 72 hour kit lists that differ from each other and it is difficult to figure out what is essential. I think that there are a few things that are essential while others will be beneficial, and others would be nice to have.
So here is what I think is the most essential items...if you get nothing else at least have these in your pack!
1-Water....at least 1 water bottle a day in your pack. Really though, if you can carry it then pack it. ......cost is about $4 for 24 bottle pack
2-Food....at least 3 days worth of food. Look at the food link for ideas. The easiest and most convenient is to get meal / calorie bars. At Emergency essentials you can taste them to see what kind you like best. I think they are chalky and bland, but I would eat them to survive. I also like Life Caps which are pills that give you what you need to survive for about 10 days. .....about $7
3- Emergency blanket ......about $1-2
4- Emergency poncho-- or large kitchen trash bag......about $1
5- flashlight with extra batteries .....anywhere from $2 and up depending on type
6- Medications- I used to be on some pretty strong medication and if I didn't have it I would get dizzy, sick and delusional....not something you want to experience in an emergency.
7- Hand sanitizer--this is cheap to add and it is important to keep yourself free from sickness....$1
8- first aid kit----you can make your own and put in a plastic bag or get a premade one for about $10
Check out the dollar store first---you can find a lot of things for your first aid kit, hand sanitizer, flashlight and batteries, and sometimes the poncho and blanket as well.
Once you get all of this in your kit you may start thinking of things that would be nice to include....hair elastic to keep my hair back, chapstick for dry lips that can be painful, and other items that are also imporant like change od clothes, pocket knife, rope....I don't know off the top of my head what I would do with the rope and knife but when you are in an emergency you learn to be resourceful and wish you had more supplies.