Sales Resistance

Be careful of, suspicious of, and just a little wary
of people who are talented in speech extemporary
who arrive with suitcases filled with cash-and-carry
items, be they vacuum cleaners or a dictionary.
Their conversation humorous, their prattle light and airy,
their smiles may be luminous, and they may be so very
congenial and friendly, their demeanor downright merry,
and yet, my friend, I recommend that you take care to parry
their sales attacks. Before you buy, please take the time to tarry
and muster up your sales resistance so you purchase nary
a single item from this flam-flam Tom or Dick or Harry.
Just shoo him from your doorstep and off to Tucumcari!

The Ragtag prompt was extempore