What does the fortune teller mean by sitting in a golden chair?

It means that you can keep money and live a prosperous life.

Golden chair is an ancient folding chair with armrests and crossed legs. It is often used as a metaphor for leadership. The "first golden chair" metaphor has the highest status. Historical records show that the golden chair symbolizes a powerful position of power.

In Water Margin, after Song Jiang reached the top of the mountain, Classical used the proposal of "Please ask Song Jiang to be the cottage owner and take the first golden chair" as a reward for saving his life.