Grocery stores have changed a lot over the decades, and so have the products that lined their shelves. Brightly designed packaging from decades past has become a category all its own, prized by collectors who love the nostalgia of vintage branding almost as much as the products themselves. What was once a normal box of cereal or a tin of coffee is now a piece of history. Finding these items today usually means digging through basements or antique shops, since most were used up and thrown away long ago. Unopened boxes and cans in good condition are especially rare, which…