I have a 20-point China People's Post, which is marked "Shanghai Folk Houses". What is the current market value of stamps?

Shanghai residential stamps are one of Pu23 ordinary residential stamps. The circulation of ordinary stamps is huge, it is estimated that there are several billion stamps, and a large number of them are used for real mailing. There are so many books on the market that selling tickets on credit is almost worthless. The new ticket collection market quotes around 0.5 yuan. The whole page 100 is a little more expensive, about 100 yuan. If it is an early full-page with large perforations, it will surpass 300 yuan.