I've been helping my neighbor do an Explorer swap, and while it's not terribly complicated, it's not exactly an overnight operation, either. Especially considering that no one in their right mind would run the stock Explorer cam, there is a fair amount of work involved. It may be cheaper to do an Explorer engine, but there is just as much, if not more, work involved with an Explorer swap than there is doing an HCI on a stock Mustang shortblock.
I don't know if I would 100% agree with that. True, a H/C/I swap can be performed on your stock engine in the vehicle, sure....but it's a whole lot easier to perform whatever tasks you want to do to the engine while it’s out of the car, bolted to an engine stand.
Another nice thing is that you don't need to remove the heads on the Explorer engine in order to do a cam swap. That's a bit of a cost and time savings right there.
I paid $300 for the low mileage Explorer engine I have sitting on my stand. It came complete minus throttle body and accessories. I can work on it, polish, clean, paint it at my leisure, dress it any way I want, everything is easy to get to and easy to see and the only down time my Mustang experiences is the time it takes me to pull the old engine out of my car and drop the new engine in. Considering how easily and quickly these engines can be removed and replaced...are you really saving any time or effort trying to do back breaking engine bay acrobatics performing a H/C/I swap with the engine still in the car? Not to mention having the engine out gives you plenty of opportunity to repair and rust, or damage located in the engine bay, of if one were inclined...to fill holes and hide wires without trying to maneuver around an engine block.

