Bulk foods from the food co-op or even the local grocery store is cheaper than packaged, usually about half the price or less. Spices are great - don't let the $22/lb on top scare you off. I just bought two heaping spoonfuls of ground nutmeg for $1.56 and barely got it all into the jar. (I use smaller spice jars and buy more frequently -- still not all that often -- so they don't go flat or stale.)
Cereals are cheap -- I just got farina for $1.29/lb. I didn't have to pay for the box that said Cream of Wheat. They also have rolled oats and grains and granola.
All the seeds I've bought in bulk sprout just fine except for the ones that say 'milled' (millet and white rice come to mind), which is where they take off the outside hull. Seeds that will sprout have increased protein, suitable for man, beast or hen, and they will grow if sown. Far cheaper than designer packages.
I have a store not too far away that seems to have sales on certain things about the same time every month. The difference between whole chickens at $0.79/lb and $1.69/lb is literally two for the price of one. Mark your calender and see if your stores do the same.
Call your most-local Cooperative Extension Service (all U.S. offices listed here by state:
http://www.csrees.usda.gov/Extension/ ). If you have a small plot of dirt in sunlight, they can help you grow things. They can also tell you where to get info on a list of local U-Pick farms. Fruits and veg are at least half the price of store food, and of MUCH higher quality. Eat it fresh, can it, dry it, make jam.
Check out some of your local grocery stores about 5 a.m. Many of them put out boxes of discarded vegetables and fruit. You usually have to pick through all the lettuce and cabbage leaves, but a lot of it is still very edible (they don't want to mix fresh produce with the older produce). BE SURE to be neat about it, and don't leave a mess.
The neighborhood you described probably wouldn't be adverse to someone who has a few chickens or rabbits. They may have some of their own. Excess eggs distributed to immediate neighbors is a nice calling card and a good way to make friends.
Sue