The least vile of all merchants is he who says: “Let us be virtuous, since, thus, we shall gain much more money than the fools who are dishonest.” For the merchant, even honesty is a financial speculation.

[Le moins infâme de tous les commerçants, c’est celui qui dit: Soyons vertueux pour gagner beaucoup plus d’argent que les sots qui sont vicieux. — Pour le commerçant, l’honnêteté elle-même est une spéculation de lucre.]

Charles Baudelaire (1821-1867) French poet, essayist, art critic

Journaux Intimes [Intimate Journals], “Mon cœur mis à nu [My Heart Laid Bare],” § 47 (1864–1867; pub. 1887) [tr. Isherwood (1930)]
    (Source)

(Source (French)). Alternate translation:

The least despicable of merchants is the one who says: Let us be virtuous so that we can make far more money than those vice-ridden fools. -- For the merchant, even honesty offers a money-making opportunity.
[tr. Sieburth (2022)]