Sam Smith is currently employed as a mechanical engineer and is paid $65,000 per year plus benefits that are equal to 30% his salary. Sam wants to begin a consulting firm and decides to leave his current job. After his first year in business, Sam's accountant informed him that he had made $45,000 with his consulting business. Sam also notices that he paid $6,000 for a health insurance policy, which was his total benefit during his first year. What was Sam's opportunity cost?