This is an $850 Ghostbuster Proton Pack replica from Viking Props (which, despite the name, sells zero horned helmets or Thor hammers). It's pretty accurate, and even has some light up effects. Even more light effects and some sound ones are available too, but at an extra cost. So yeah, you might be better off building your own out of parts salvaged from a neighbor's garage. And by salvaged I obviously mean stolen. Just don't touch his pin-up calendar.
Hit the jump for a couple more shots and a short video of the gun's light effects.
Thanks to Lackey, who busts ghosts the old fashioned way: red-handed trying to steal chains from the hardware store.