Morphy's is bidding on a special order that would require 780 liters of material W34C. The company already has 640 liters of this raw material in stock that originally cost $8.30 per liter. Material W34C is used in the company's main product and is replenished on a periodic basis. The resale value of the existing stock of the material is $7.60 per liter. New stocks of the material can be readily purchased for $8.35 per liter. What is the relevant cost of the 780 liters of the raw material when deciding how much to bid on the special order? \begin{tabular}{|l|} \hline$6,376 \\ \hline$6,481 \\ \hline$6,513 \\ \hline$5,928 \end{tabular}