Your Ghostbusters Proton Pack has been a dream of yours. There are many options: you can find a cheap toy or 3D print, sand, and paint yours, hire someone to do it, buy a premade kit or build something from scratch.
This sixth method is the most cost-effective and easiest: You can pay Hasbro $400 to get this amazing-looking item.
Hasbro claims that the Ghostbusters Plasma Series Spenglers Proton Pack was based on 3D scans from the original movie prop from Ghostbusters Afterlife. It includes lights, sounds (from 1984 and 2021), and a cyclotron that you can open and dismantle. There are also straps so you could wear it.
My Ghostbusters-loving friend was able to provide context. He had been trying to build his own body kits for years and was impressed at the price.
You will still have Hasbro's version. Some take pride in making their own versions, much like the Star Wars fans who are searching for the perfect Han Solo DL-44 blaster replica or perfect Star Wars lightsaber. You will still need to learn how to add a plasma weapon: Hasbro's $125 version can be purchased separately.
This crowdfunded prop / toy is not scheduled to ship until spring 2023. The company promises a single production run, so you have until December 12th to decide whether or not you want to be in the HasLab product. It is still a mystery to me if I was wise enough to skip the $350 Mandalorian Razor Crest. However, the Lego versions are quite good.
As I said recently, it's never been a better moment to be a grownup child.