How many rolls for $9? They cost $3 in the supermarket...

One roll. Unfortunately for me, neither my supermarket, Target, or Walmart carry this product. I use it for applique in my quilting projects. This will last until I stop quilting or die, whichever comes first.

Is one of the sides Shinee

Yes, one side is shiny. The paper can be ironed to stick to fabric with shiny side down and can be reused 4 to 5 times, because it peels away easily.

Is the plastic coating BPA-free?

Don't know I use it for art transfers

why freezer paper over freezer bags to store meat?

Freezer paper has been around many years longer than freezer bags. Similar products is now used at the meat counter by the butcher. I use freezer paper for craft and sewing projects.