Yongmaoyuanji or Yongmaoyuan is the earliest Tang name in the Jiaqing period. It was a trademark on porcelain in the Qing Dynasty and also a merchant brand. I don’t know what kind of porcelain you are talking about. Is it a plate, a bottle, or other shapes? Generally, a complete plate should cost between a few thousand yuan. If it is a porcelain of other shapes, it will range from 10,000 yuan. It's best if you give me a picture or the shape of the porcelain before I can give you an estimate.