Thank you for submitting your item for apparaisal. This appears to be a japanese Noritake dinner service, the P 509 pattern which was in production from the late 1970s until 1991. This porcelain is dishwasher safe and therefore easier to sell than the pre-war Noritake porcelain. The estimate is based on similar offered in the recent past. The demand is rather limited. The low estimate is for the dinner service sold as a whole, the high estimate would be the result if you offer and sell each item individually for those who need a replacement over a long period of time.