How to ID a real MP 360 crate magnum, id the HP rating, and what's it worth?

Someone is advertising a new Mopar crate 360. Has the black aluminum Magnum covers. "In the crate." Has a partial photo of the MP literature, and what would I pay?
I'd guess 5k or so (380hp) because figure if you build one and use better aluminum heads and better rods you might spend $7,500 or so. ps so everyone doesn't kill me these are just approx. prices.