Did Aristotle think the job of "Salesman" was the "lowest" perhaps least virtuous job a man could have?
Aristotle was critical of trade in general. He called use value "true wealth" and exchange value "spurious wealth". Correspondingly, "natural exchange" is the exchange of something less needed for money to buy something more needed, while "unnatural exchange" is the purchase of things to sell later at a higher price. In the former case the end is more use value and the means is money, and in the latter the end is more money and the means is use value.
So according to Aristotle, whether a salesperson is virtuous (at least with respect to their business) depends on which kind of exchange they are engaging in.
And there is another kind of moneymaking, interest (called τόκος in Greek), whereby money increases itself. And so the Greeks called it τόκος, since that means offspring. For we perceive that things generated by nature are like the things generating them. And so there is a kind of generation when money increases from money. And so also such acquisition of money is the most contrary to nature, since it is according to nature that money is acquired from natural things, not from money. Therefore, one kind of moneymaking is praiseworthy ["that acquires money from natural things (e.g., crops and animals)"], and three kinds [(1) "commerce…transformed from what is a necessity of nature to what desire demands", (2) "lending money for a fee", (3) making money from money] contemptible, as he has said.
Thus, a salesman isn't sleazy, according to Aristotle, only if he acquires money from natural things—not by making people desire to buy what they don't need (1), nor by lending money for a fee (2), nor by usurious lending (3).