Giovanni Battista Mercati ( 1600 - 1645 ) was an Italian painter. Giovanni Battista Mercati s works have been put up for auction numerous times, with realized prices varying from 425.71 USD for Die Enthauptung Johannes d.T. in 2005 to 681.14 USD for Der hl. Atonius von Padua in 2005 , based on the size and medium of the artwork.