If you check the tires and they are original equipment, you definitely need to consider negotiating replacements in your pricing. You WILL be buying a set real soon if you are planning on towing most anywhere. One flat and you will be quickly convinced. My previous RV was a 2005 TT. In 2008 took a trip (700miles roundtrip). Tires were manufactured in 2004. Gone; new tires installed.
I am not saying you need to panic and replace the tires, BUT, common sense will direct you when it's time to make a switch. Also look for uneven wear patterns.
Does not take much to make a good trip go bad. One flat on an interstate or a narrow country road with no shoulder isn't gonna be a happy camper time.
Just because a tire looks good; tread, etc, does not mean it can sustain load and stress. As a motorcyclist, I know the value of tires first hand. It's the only thing separating your butt from the road.
Life is short.....enjoy.