How can I find out how much a painting is by Countess Zichy?

Question: How can I find out how much a painting is by Countess Zichy!?
Best Answer - Chosen by Asker:

I have to say: which Countess Zichy!? There are certainly two who are easy to google, and many portraits by famous artists of Countess Zichy (rather than BY her)!. The older Countess had an unhappy marriage to the Count Zichy, who was a painter, and was the mother of the other one!. As your picture is by or of someone well-known, it is certainly worth showing to a good art auctioneer such as Christy's or Sotheby's!. They would give you an idea of current prices by any known artist, but the art market can be unpredictable!.Www@QuestionHome@Com