What are they selling? There's some badass words for specific vendors. Like haberdasher... never been able to work this one into my writing, but I'm holding out hope.
http://www.thesaurus.com/browse/salesperson?s=t Don't miss the page navigation at the bottom for more options. There're plenty there. I usually have this and its complimentary dictionary open in two windows on my other monitor, both windows side by side.