How much does a new tower cost?

I'm curious, could you elaborate on the factors that influence the cost of constructing a new tower? Is it simply the materials and labor, or are there additional expenses such as permits, zoning regulations, and potential environmental impact assessments that need to be considered? Additionally, does the size and complexity of the tower play a significant role in determining the overall cost? I'm eager to gain a deeper understanding of the financial considerations that go into such a project.