Grégoire Mathias ( 1967 - ) is a painter. Grégoire Mathias s works have been put up for auction numerous times, with realized prices surpassing estimated prices, varying from 1498.68 USD for Composition √† la guitare in 2009 to 1780.05 USD for L'affaire de la Chambre 12 in 2009 , based on the size and medium of the artwork.