Two years ago the manager of a large department store

Two years ago the manager of a large department store purchased new bar code scanners costing $39,000. A salesperson recently tried to sell the manager a new computer-integrated checkout system for the store. The new system would save the store a substantial amount of money each year. The recently purchased scanners could be sold in the secondhand market for $19,000. The store manager refused to listen to the salesperson, saying, “I just bought those scanners. I can’t get rid of them until I get my money’s worth out of them.”
What type of cost is the cost of purchasing the old bar code scanners? What common behavioral tendency is the manager exhibiting?