Patriots,
Don't fall for those super expensive 30 day food supply crap.

1) While it will last for 50 years you will not need it for that long, not even close. You may not even need a month, I am thinking 10 days to 2 weeks.
2) Some of those meals (most) require water. Water will be at a premium so using it for food isn't a good idea.
3) A lot of those need to be heated to re-hydrate so unless you have a place to heat things with no electricity you are going to have mush.
4) Normal canned goods last for years and can be eaten straight from the can. These are not only cheaper but also contain water which will help you stay hydrated and consume less actual water without ill effects.
5) You can keep a fresh supply of canned goods by just rotating the cans with your normal meals. Remember you can go a long time with no food but only a few days with no water. Have at least half a gallon per person per day.

Save money and be smart.

I'm making pemmican (easy to do if you have a food dehydrator). That stuff has a many year shelf life, costs little to make, and provides more than a couple thousand calories per square. I dry a lot of foods, if elect is off for more than a couple days, I'd lose what I have stored in the chest freezer. Have solar lights down the sidewalk, when power goes out (it does a lot here), I pull them up and stand them up in a glass (cheaper than flashlight batteries!) For other kinds of supplies, check out an Army surplus store (a real preppie treasure trove!)