Although the internet is a vast repository of information, it does not contain all-encompassing information. Your original painting has been in private hands and thus would not be online, until now, essentially. It is an original work by the American painter, William Merritt Post (1856 - 1935) . He was a tonalist painter known for landscape/creekside and harbour views. He is associated with the Barbizon school. He was a prolific painter and has a lengthy record of auction sales. The estimate factors in the condition issues and is based on actual recent past recorded auction sales of comparables. Retail 'asking prices' can be higher and vary.