Factors Affecting the Cost of Capital. The marginal cost of capital (MCC) is the cost of the last dollar of capital raised, essentially the cost of another unit of capital raised. As more capital is raised, the marginal cost of capital rises.With the weights and costs given in our previous example, we computed Newco's weighted average cost of capital as follows: WACC = (wd)(kd)(1-t) + (wps)(kps) + (wce)(kce).actors Affecting the Cost of Capital. The marginal cost of capital (MCC) is the cost of the last dollar of capital raised, essentially the cost of another unit of capital raised. As more capital is raised, the marginal cost of capital rises.