$13\mathrm{.}30.$ The office manager for the Metro Life Insurance Company orders letterhead stationery from an office products firm in boxes of $500$ sheets. The company uses $6,500$ boxes per year. Annual carrying costs are $$3$ per box, and ordering costs are $$28.$ The following discount price schedule is provided by the office supply company:

$\backslash$table$[[$Order Quantity $($Boxes$),$Price per Box$],[200-999,$$$16$