The profit margin of a small builder may differ based on various factors such as location, size of projects undertaken, market demand, and the builder's reputation or specialization. On average, small builders tend to aim for a profit margin around 15-20%. This range allows them to cover their operating costs like labor wages, subcontractor fees if any, permits/licenses, insurance coverage, administrative expenses, tools/supplies procurement while making a decent profit. However, it's crucial for small builders to continuously assess their financial performance and adjust their pricing strategy accordingly to ensure long-term sustainability in an ever-changing construction industry.