According to the information you provided, this blue-and-white plate may be a "Japanese applique blue-and-white porcelain plate" during the Republic of China. This type of plate can generally sell for about 2000 yuan in the market. However, the actual price may be affected by many factors, such as the appearance, preservation status, market conditions and so on.
As for the size, the size you provided is 3 1x40, but please note that this does not completely determine the exact age of this blue-and-white disc. Plates of the same size can be made at different times. If you need more accurate dating information, I suggest you consult a professional antique appraiser or do further research.