Who is Malgras from The Masterpiece and what is their importance?

Malgras is an rather art dealer who knows nothing about art. He does, however, have an for a piece that will turn a profit. A crafty businessman, Malgras manages to get excellent paintings from Claude and other artists at ridiculously low prices. He senses when an artist needs money desperately and regularly feigns disinterest in the very paintings he will end up buying.