The original reason for my family was that my dad was having to go on disability and still had 5 kids at home to feed. Things were really tight the year he had to wait to hear about if he had actually been declared disabled and he couldn't work during that year. That was the first year of our homesteading. It was all very bare bones and done on a string, no utilities, no running water, a log cabin we built in three weeks time on a brush and brier filled plot in the middle of a 100 acre tract of land. It would take a whole book to describe how little we had back then and how we managed, but manage we did and we ate very well off the land, though much work was involved. Knowing now what I didn't know then, I could have made it an easier row to hoe, but back then the internet was not available(70s) and Mother Earth News was about the only source of information on getting back to the land.
Because of that journey, I was so impressed with how little a person can actually live on if they have to. Since then I've been raising most of our own food and trying to keep the overhead down to a minimum. Start up costs for getting chickens and even establishing a garden seem like a lot to some people and they can't imagine ever making that money back, but it happens...and especially if one starts small and builds, uses materials that are free, scavenges for more of the same and studies up on how best to keep costs down and production high. As a single mother of three boys, I would never have attempted it at all if I couldn't do it cheaper than buying the stuff from the store.
Home grown foods can't really even be compared with store bought foods, as they surpass them in taste, nutrition, freshness and purity. No one can really break down the costs of what such a diet does for the general health of the family, but I can compare our health and the health of others living in the same area, attending the same schools/work place, etc. and there is really no comparison. Their health costs are high and they are frequently ill, we are rarely~if ever~sick and our health care costs are usually nothing at all, or small and once in a blue moon~teeth, eyes, OTC this or that.
Then there is the good mental health that is provided by caring for animals and the land, growing things and constantly learning about how to improve on that. It's a wonderful outlet for artistic expression, for the thirst for knowledge and for interaction with the world around us. Gets us off the couch, outside in the fresh air and sunlight and learning new things all the time, keeping our brains and bodies active.
But, most of all, it really and truly is cheaper than buying from the store in plain dollars and cents. One just has to realize that it doesn't have to happen NOW and one doesn't have to have the cutest coop, the most colorful and cute chickens and the garden doesn't have to have mulch trucked in and deposited in order to produce food. It can all be a slow build, gained free or very cheaply, and grow from there. One has to re-prioritize their lives and their thinking about food in general. It takes work...sometimes it takes a lot of work or work that is not fun to do. But it's worth it all. Just like any other endeavor that is supposed to save you money....go slow, keep overhead down, strive for the best production and always...always...be looking for free things that will help you along the way.
Another thing to remember...you can't eat sentimentality.