The info above gives good insight.
Also, remember the mfg trailer weight is a 'dry weight' and does not include the weight of the battery, propane, accessories added, etc.
You are wise to question the sales person as had one try to sell me a unit and stated it was under the weight maximum for my pickup & would pull it fine. He was correct as long as the unit was as delivered from the factory and totally empty!
I'm so glad I checked before making a hasty purchase based on the sales persons word along.