To maslow and humanistic theorists, reflects the humanistic emphasis on positive aspects of human nature

I believe the answer is self-actualization
According to Maslow, self-actualization refers to the highest sense of achievement that a person could feel in our personal life.
This could happen in various forms. For example, some people feel self-actualization by doing good for community, some people feel self-actualization after they managed to achieve their life-long achievement, some people feel self-actualization if they could committed to a certain diety, etc.

Complementary goods. they go together, thats why one price increase and the others demand increases