Thank you for submitting your item for appraisal. This appears to be a japanese Imari style transfer printed plate, marked at the back "Imari". The Artemesia leaf designs at the underside are identical, therefore most of the plate is printed, there might be a few painted areas. Transfer printing was invented in England some 200 years ago, but became common in Japan after the 1950s. The estimate is based on similar last quarter 20th century japanese imari style plates sold at auction. There is no measurement for the sentimental value you might attach to it.