Answer:
The opportunity cost of each pipe and what is the sunk cost is $77 and $67 per pipe respectively.
Step-by-step explanation:
Opportunity cost: The opportunity cost is that cost which is incurred to choose the best options with the available options.
Sunk cost: The sunk cost is that cost which is not recovered in the future. Its other name is the past cost. It does not help to make future decisions as if it is incurred then it cannot be recovered again
So, the opportunity would be the current price i.e $77
And, the sunk cost is $67 per pipe ($77 - $10)