The OP might be better off buying a relatively new unit instead of new if he is worrying about the little stuff like sewer hoses etc.
When the day comes that ours is sold somebody will get a 'turnkey' rig. All they will need to put onboard will be their clothes & food. EVERYTHING will go with it, right down to whatever gas is left for the genny.
Buying new may be nice but all the stuff needed to make that new unit usable can exceed $2000.00 real quick. If on a budget, look around for a direct sale. The owner is more likely to include much more stuff. New or used a dealer is most likely selling a stripped rig.