Self-paced training is designed to be highly automated to make MuleSoft training accessible to tens of thousands of people per year at zero cost to the students and low cost to MuleSoft. Instructor-led training involves interaction with an instructor, additional support from the Training department and an accelerated learning schedule. All of these enhancements have substantial costs, requiring us to charge a fee for any Instructor-led training. As with many businesses, the free option is great if it works for your scenario and the paid option is available for those with additional needs.