Welcome to the forum.
First of all your Ram 1500 is not a good combo with a toy hauler. The tongue weight is way too much for that truck, see sticker for weight limits on driver side door post to comfirm.
Next my opinion only is that a 8year old toy hauler in which you have no idea how the previous owner treated it, over loading, driving over roughy terrain etc. you're taking a chance. The dealer is just trying to make a sale, once it of their lot it's you're problem unless they willing to give you a written agreement that if the frame has a issue they will repair within a reasonable time or exchange for another TT. If not, then walk no run away.
We'll see what others here have to say but like I said it's just my opinion.
Loving wife and 2 beautiful daughters.
Chocolate Lab, Lily
2014 Dodge Ram Laramie Hemi 5.7 with 3.92
2014 Dutchmen Kodiak 290BHSL
ProPride 3P Hitch
Progressive Industries EMS-PT30C
Love my Weber Q1200
Me a Happy man on retirement!!!