A manufacturing firm receives a bid from a local construction company to build a warehouse for $\$ 300,000$. The firm decides to build the warehouse itself and does so at a cost of $\$ 250,000$. Why is it that GAAP do not permit the firm to record the warehouse at $\$ 300,000$ and recognize revenue of $\$ 50,000$ ? How will net income differ if the firm follows the generally accepted procedure versus recording the warehouse at $\$ 300,000$ ?