In the early 70's, my mother would spend ~$25 per week on several bags of groceries. This would feed a family of 5 very well. By the end of the 70's, after the Carter Era double-digit inflation, it was closer to $100 for a family of 4 (my sister was married by that time).
I remember as a child listening to old men talk about filling up a 2 horse wagon with groceries for $5. I imagine at that time though the groceries consisted of salt, sugar, flour and some other staples because everything else they needed was grown/raised on the farm.
I remember flour coming in 50 and 100 pound sacks. The sacks were of a fine printed cotton material that women made shirts, blouces, dresses, pillow cases, quilts and other items from. Daddy ran a country store in the 50's and women would come in and shop for flour more by what the sack looked like than what was in them. Sometimes they would buy a sack of flour and didn't need it just because they liked the pattern on the sack. Some animal feeds came in similar sacks back then.....not so today.