Marigold Corp. has several outdated computers that cost a total of $17800 and could be sold as scrap for $5800. They could be updated for an additional $2800 and sold. If Marigold updates the computers and sells them, net income will increase by $9000. What amount would be considered sunk costs? \begin{tabular}{|} $17800 \\ $9000 \\ \hline$2800 \\ \hline 320000 \end{tabular}