For point 7, why is there an opportunity cost of 3000? If we keep the machine and use it we can’t sell it immediately but can’t we just sell it at a later date? We are not told otherwise. Maybe it will be worth a bit less than 3000 but we will not lose out on the proceeds of the sale, regardless?
If we did not do the work then we would sell the Swipe and get $3,000.
If doing the work means that we cannot sell the Swipe, then we are losing $3,000 that we could have received – an opportunity cost.
If we do use it in the work, then we cannot sell it at a later date – it is used in the system that is sold to the customer and so it would no longer be ours to sell.