Eir$-$Tel, Inc. is a telecommunication services provider looking to expand

to a new territory Z$.$ It is analyzing whether it should install its own telecom

towers or lease them out from a prominent tower$-$sharing company X$-$share,

Inc.

Leasing out $100$ towers would involve payment of $5,000,000$ per year for $5$

years. Erecting $100$ new towers would cost $18,000,000$ including the cost of

equipment and installation, etc. The company has to obtain a long$-$term

secured loan of $418,000,000$ at $5\%$ per annum. Owning a tower has some

associated maintenance costs such as security, power and fueling, which

amounts to $10,000$ per annum per tower. The company$$s tax rate is $40\%$

while its long$-$term weighted average cost of debt is $6\%.$ The tax laws allow

straight$-$line depreciation for $5$ years.

Determine whether the company should erect its own towers or lease them

out.