Salesmen are always anxious to get a sale, and the unscrupulous or or more ignorant ones will tell you that your tow vehicle can pull any trailer that they suggest you would love to own, and which they just happen to have on special today, priced to go. Challenge them to prove the capability of the tow vehicle on paper and I bet they would have NO CLUE. Heck, I have even spoken to some who were not RVers and / or who have no experience towing anything.
Best advice - one should do their homework by conducting prudent research including verifying the credibility of the sources of the info. Then, once armed with the maximum trailer gross and tongue weights the TV can handle, check the market and IGNORE the salesmen when it comes to towing.