So it's easier to "add PW attributes" to a 3500 versus swapping out some suspension components? The average home mechanic can swap out rear springs, shocks, and add airbags to a PW on a Saturday afternoon for just over $1,000 in parts (in my opinion the $400 airbags would do it). You are going to have $3,000-$4,000 just to add locking differentials front and rear, and very few home mechanics have the experience or tools to do this. Then add the cost of a winch and mount (over $1,000 even with a cheap winch), a little suspension lift, and not even sure what you would do about the disconnecting swaybar.
I agree that a stock 3500 would work "better" when simply considering hauling stuff down the road. But I don't agree that it would be cheaper or easier to upgrade a 3500 to the same level as a PW for off-road capability.