Siegfried Zademack ( 1952 - ) is a German painter. Siegfried Zademack s works have been put up for auction numerous times, with realized prices surpassing estimated prices, varying from 627.77 USD for Testsprung in 2004 to 1704.62 USD for Unendliche Quellen - Toiletten in der Wüste in 2007 , based on the size and medium of the artwork.