Please tell me why the tower cranes in Shandong are so cheap! What is the difference between expensive and expensive?

Shandong people have high quality, fierce competition, advanced equipment, less labor force and low cost. They use bigger and better materials at the same price. What is the relationship between Q235 and Q235B? You can't figure out why the manufacturers in Shandong are not good and use inferior products. My personal opinion is that as long as it is a tower crane manufacturer outside Shandong, hundreds of people are selling it every year.