Jacob Willemszoon de Wet

Houbraken mentions him in passing as an art dealer of Haarlem in his biographical sketch of Philips Wouwerman, referring to him as Jan de Wet.

[3] Houbraken relates a story in which Philips Wouwerman burned his sketchbooks before his death, so that his brother Pieter wouldn't be able to use them and cash in on his name.

Apparently after Pieter van Laer had returned to Haarlem, he received less for his art than in Rome, but he refused to lower his price.

When a landscape that van Laer had made was considered too expensive by Jan de Wet (a dealer), the buyer contracted the then young Philips Wouwermans to copy it, which he did quite well.

[1] Judging from the number of pupils, and the difficulties his son Jacob II had with launching an independent career, it seems that De Wet had a large and successful practise in Haarlem.