I am not sure you had to pay extra for an automatic 02 FX4. If so, it was not much more. I do know it was much less difficult to find an 02 FX4 with an automatic than it was with a manual. I went through that search and experience it myself.
There was a bit more to a FX4 than just better shocks and rear axle. They also had the Alcoa wheels with 31" BFG AT tires, stainless steel front tow hooks with a tow hook in the rear, skid plates and more durable seats. It was much more capable off-road from the factory than a standard XLT. Sure you could build the same thing yourself from a XLT but I doubt you could save money doing it. Plus you would spend a lot of time working on it rather than being out doing what it was meant to do. Mine has served me well and is still providing my off-road fun at 242K miles. It has been upgraded a little through that years though.
I will add my assurance to the OP that the Ranger in questions is truly an authentic FX4. Either that or someone went to a lot of trouble and expense to imitate one.