Usually the only way you can reach them is through a P.O. mailing address. Tell the seller you'll check it out and get back to them. Don't buy on impulse. You can do business on your own terms. Take the time to investigate both the seller and the offer.
Workers drive a pick-up truck through a neighborhood in which older people live.
They approach people outside their homes. They perform shoddy work that is completed very quickly. They demand cash payment. They refuse to provide references or a warranty. The final price you are asked to pay will be much higher than the initial estimate.