and this.  freeze dried is like MREs--a very useful tool to solve a particular problem, but not a solution.  the main advantage of MH is that it doesn't weigh much.  the tradeoff is that it takes potable water to prepare.  so it's a great idea if you plan to move around a lot, weight is an issue, and water is not.  unless those three criteria are met, you almost certainly have more nutritious and less expensive options available.

You need water to prepare them, but you also need water to survive. You are ingesting the water you use to make them, not wasting it.  
If you do not already have water you are in bad shape.
But like you said, if you plan on staying in your house/wherever, canned food from the grocery store is a lot cheaper.  Rice and beans are REAL cheap.

If you can get some free food grade 5 gal buckets, you're $150 will go a long way.

Fill some buckets with rice, fill some with beans and make sure to fill one with spices, sugar, salt, pepper etc. You can buy mylar storage bags and oxygen absorbers online, seal them with an iron and the side of a metal level.

I would make a first aid bucket with rubbing alcohol, bandages, neosporin, + anything first aid related.

Camp style cooking kit, cheap metal pots, pans and utensils, lighters + a pack of propane canisters.

A way to purify water. You can boil it, use iodine tablets or get a water purifier pump $$$.

I have one bucket with a toilet seat lid and I keep it stocked with TP, wet wipes and a quick shower kit = soap, shampoo, razor etc.

Lots of small and large garbage bags for trash, poop or quick storage.

Reiterating what's already been posted: Water, water, water! You can survive a long time without food. Without water you'll be in a dire situation in a matter of hours. Also consider that dry bulk foods (rice, beans, oatmeal, pasta) and dehydrated foods require lots of water to cook. Stay away from Wise Foods. MREs are a short term option, but they are expensive and not suitable for extremely long term storage (about 5 years is their limit, if memory serves). Keep in mind that in practically any "bug in" situation that you will have several gallons of fresh water in your water heater if you have a conventional model with a tank, assuming, of course, that the public water system was not tainted during/prior to said situation.

Another two gallons in each toilet tank.
If you have a pond or swimming pool you will be sitting pretty.  

Read the novel Patriots.  Rawles will square you away.

and they require a lot more water in order to digest, totally aside from the very high sodium content (which draws water out of your cells).  you're not going to hydrate by eating mountain house--it is likely to increase your hydration needs beyond that which is required for non-dehydrated foods.

again, it's a tool for a specific job.  if weight is an important issue, and you have plenty of available potable water, then freeze-dried is very helpful.  otherwise, there are much more suitable (and less expensive) tools.

Beans can be sprouted and eaten raw.  No cooking is required.

Buy a water filter before anything else.  Then buy some spare cartridges.  Something that is enough to provide clean water for your whole family each day efficiently.  

When you're in a 3rd world shithole, there's always something to eat somewhere.  Clean water?  Nope.  And the same would apply here within a day or two of the lights going out.


Then get some rice, beans, shortening, salt and multivitamins.


And start reading up and hanging in the Arfcom Survival Forum.