Bad idea to buy a 2015 truck from a dealership?

So far the winner is this green boy right here. Clean coolant, dry engine, no weird oil anywhere that I can see (except near the oil drain hole). No bad codes. Used to belong to Interstate Batteries. But it does have the dancing EGR valve thing at idle. And sort of a weird rotten garbage smell in that area when the engine is running. Is this something easy to fix, or should I pass on it?

 

Yeah, I have family in CA that I like to visit, and honestly I believe in DEF, even though it's a hassle.

 

Yeah, the thing is kinda loaded. Fridge, inverter, and even that super rare and fun escape hatch that makes it feel like you're camping

 

Pricey. 67000 for 440,000 miles. But it does have level 4 warranty until 500k miles, the type of warranty that does cover emissions stuff.

And also, this is a Freightliner/Penske dealer, so they are playing it like a certified preowned thing, 60 day comprehensive warranty and 1 year/100k mile limited warranty included. I'm a little sceptical about all that, to be honest...