Kos Koolhaalder ( 1868 - 1957 ) was a painter. Kos Koolhaalder s works have been put up for auction numerous times, with realized prices varying from 366.39 USD for Rozen in vaas in 2004 to 447.81 USD for Stilleven met bloemen en vruchten in 2004 , based on the size and medium of the artwork.