A basic sandwich recipe uses about 550 grams of flour (mine uses 553), which means that a 50 pound bag makes roughly 40 loaves (the math divides to 41 loves, but life is imperfect, so I use 40 as a benchmark). A fifty pound bag takes up 8-10 gallons of storage space.
If you make 3 loaves of bread each week, a fifty pound bag of flour will last about 13 weeks, or one quarter of the year, making a bulk purchase reasonable if you can accommodate the storage. I like to store things in glass whenever possible, and I promise you that even if such a thing as a ten gallon mason jar existed, it would be useless for me, since I would have nowhere to put it and wouldn’t be able to wrangle it, even empty. I have a few 2.5 gallon jars, and that’s about the maximum I can handle at a time, and about the largest that fits on the pantry shelf. I find that dividing up the bag into 4 jars and rotating them out is perfectly serviceable. 550 grams is about 1.5-2 quarts, so if you prefer, you can fill a few 2 quart containers with pre-measured flour to make the upcoming baking more streamlined. This also helps younger children (or distracted adults) and helps separate the task of weighing the ingredients from the baking.
If you only make a single loaf each week, it might make more sense to divide the purchase of a 50 pound bag with another family as opposed to storing it for most of the year (the per-pound savings are eye-popping enough to make a bulk buying group worth the time to set up).
If you plan on storing bulk flour for longer than a few months, I strongly recommend a glass jar with a rubber ring at the seal and a spring closure. Flour is too attractive to every little pest and mite to leave this to chance, and there’s nothing sadder than opening a bag only to find it infested. (If it gets infested with weevils, put the flour in a freezer container and set it in the freezer for three days or more to kill the weevils and eggs. You can pick out or sift away the dead bugs and use the cleaned flour for baking or any of the scads of non-food uses for flour. If the flour is musty or clumpy, or shows visible mold, it’s ruined; throw it out).
You don’t have to be a homesteader to appreciate having freshly-baked bread on hand.
The aroma alone is worth it.