There was such a thing in the Han dynasty at that time. Because of the treasury at that time, the emperors of the Han Dynasty often sold officials and titles. Because the battle for hundreds of officials often has talent selection, and official positions are often the direction people yearn for. Because the country is rich and the people are safe, having an official position means having a rice bowl, and the state gives officials money as wages to maintain local wages, while people with official positions can gain a foothold in the society at that time and stand on the people's side.
Because official positions are authoritative everywhere, many people are keen on buying officials. The king allows this because selling officials and titles can be used to supplement the treasury, and the enrichment of the treasury is the king's favorite point.
Because buying an official is the idea of ordinary people, and it is something that people with certain wealth accumulation are willing to see. Selling officials is what the king needs to fill the national treasury, so it is often a matter of interest cycle.