Answer:
James's price is $4 less than if the firm is a monopoly. A further explanation is given below.
Explanation:
Marginal income should have been equivalent to the marginal cost expenses as there was a Monopoly. The marginal price is calculated at 8 dollars. That being said, marginal income is declining.
When making the 4th unit, no marginal income as well as marginal cost becomes nearest. It, therefore, means that, as it generates 4 units, the Monopoly price would have been $12. Whether it is a reasonably open market, the cost should always be equivalent to marginal revenue, meaning $8 would be the price.