For a snapshot of the cost of living in the Bicentennial year, this ad for A&P stores appeared in the Pittsburgh Post Gazette on March 5, 1976.  While the prices look low, this was the era of the WIN button, and there was a lot of inflation in progress.  According to this online calculator, one dollar in 1976 works out to $5.58 in 2025 dollars.  So 59 cents for a five pound bag of flour works out to about $3.29 per pound today.  You can check the current price at Amazon at this link.