It costs Cullumber Company $$7$ of variable costs and $$3$ of fixed costs to produce its product at full capacity. However, the company currently has unused capacity. The product sells for $$15.$ Ivanhoe Company offers to purchase $3180$ units at $$9$ each. Cullumber will incur special shipping costs of $$2\mathrm{.}50$ per unit. If the special offer is accepted and produced with unused capacity, net income will

increase $$1590.$

increase $$6360.$

decrease $$6360.$

decrease $$1590.$