I towed a 32 foot triple slide fifth wheel for three years with a Dodge Cummins 3500 dually 4X2 truck. Never got stuck, never needed four wheel drive. It did, however, have a limited slip differential, and I always had aggressive traction tires on the rears.
Now, the truck in my sig. is 4X4. Not because I NEED 4X4, but simply because finding a 4X2 is nearly impossible these days. So many people are convinced they just have to have a 4X4 that used 4X2s are very rare.
As for resale value, I have never understood that. I seldom buy anything with an eye out for what I can sell it for. I buy it to USE, not SELL!