The big auction houses will give you an estimate of the paintings worth, their fee is 10% of the estimated worth. The big auction houses set the price level for the Art Market so their estimate is usually pretty good.
On the other hand, a dealer who specializes in Kiesel told me it was worth only around $1000 in the present market. He doesn't put the prices he asks on the web.
Thanks for the advice. alohapolitics.com