The state capital in China with the lowest housing prices is generally considered to be Changchun, the capital of Jilin Province. This city has consistently ranked among the least expensive in terms of housing costs, particularly for new residential properties. The reasons for Changchun's relatively low housing prices can be attributed to several factors.

Firstly, Changchun's population growth has not been as rapid as in many other Chinese cities. This slower growth rate has led to a more balanced supply and demand for housing, which in turn has helped to keep prices down. Additionally, the city has not experienced the same level of investment in infrastructure and real estate development as cities like Beijing, Shanghai, and Guangzhou, which have seen significant price increases due to high demand and limited land availability.

According to data from the National Bureau of Statistics of China, the average price per square meter for new residential properties in Changchun was approximately 5,200 yuan (about $770) as of the end of 2021. In comparison, the average price in Beijing was over 51,000 yuan per square meter, and in Shanghai, it was around 47,000 yuan per square meter. These figures highlight the stark difference in housing affordability between Changchun and the country's major urban centers.

Another factor contributing to Changchun's low housing prices is the city's economic structure. Jilin Province, where Changchun is located, has a more diversified economy compared to some other provinces that heavily rely on manufacturing or heavy industry. This diversification has helped to create a more stable economic environment, which is less susceptible to the fluctuations that can drive up housing prices in other regions.

Furthermore, the government of Jilin Province has implemented various policies to promote affordable housing and control prices. These include providing subsidies for low-income families, limiting the number of apartments that can be sold to non-local residents, and encouraging the development of affordable housing projects. These measures have helped to maintain a level of affordability that is not as prevalent in other parts of China.

In conclusion, Changchun, the capital of Jilin Province, has the lowest housing prices among China's state capitals. This is due to a combination of slower population growth, a more balanced supply and demand for housing, a diversified economy, and government policies aimed at promoting affordability. The data from the National Bureau of Statistics of China supports this analysis, showing that Changchun's housing prices are significantly lower than those in the country's major urban centers.