La. R.S. 39:1710

When a local governing authority purchases an item at the state bid price through a local vendor, the local governing authority may pay to the local vendor the costs for shipping, preparation, and delivery of the item, provided that these costs shall not exceed the state bid price by seven percent on purchases up to ten thousand dollars, five percent on purchases over ten thousand dollars and up to twenty thousand dollars, and three percent on purchases over twenty thousand dollars.