All in perspective, to us 2 rail O scalers that is a pretty good price for detailed kit of that locomotive.
For that price and from you description "body kit" that is what I assume it is. This means it is the shell only, there is no mechanism.
It should include all the detail parts to finish the shell, including all the grabs and hoses, pilots, lift rings etc. I have built some of these P&D kits and the ones I have dealt with include hatches and fans to make it either with or without dynamic brakes.
P&D Hobbies still has some kits in stock, and if you called, I think Pat (the owner) could give more details about the details. They also have additional parts to customize the units.
And they have power kits for 2-rail. that are pretty expensive too, but very nice. A couple hundred I think.