This document provides information on costing and modeling for an entrepreneurial venture. It defines fixed and variable costs, and provides an example of costing out a business idea of painting games on school playgrounds. The document estimates fixed costs such as website and supplies, variable costs like paint and transportation per game. It models the potential market size and revenue based on number of schools and percentage that may purchase. By estimating costs and potential earnings, it demonstrates how to calculate total costs and potential profit for a venture to evaluate viability.