Porch and Patio paint cost anywhere from $30-70 a gallon and is made to withstand a little more wear and tear. Exterior Quarts of premium paint with a primer (which makes the paint coat better) is about $15-20 a quart.
You will also need 4 to 10 paint brushes and a couple of 4 or 6-inch rollers, and disposable paint trays or plastic plates and cups. Number of brushes and rollers depends on how many colors and people are willing to help with your project.