1760 D. Webb Pref. 11 An idle art more useful to a picture-merchant, than becoming a man of taste.
1828 J. Kenney i. i. 14 ‘Who's there?’..‘A person from Isaac, the picture-merchant.’
1995 (Nexis) 2 Aug. c4 Nowinski is a local art collector... He has no experience as a picture merchant.