After trapping Slimer in Ghostbusters: The Video Game and witnessing Bill Murray’s excellent cameo in Zombieland, there is only one true Halloween costume option this year. Lucky for you, and much like Peter Venkman’s multi-tired laundry system, there are a good number of options available for aspiring Ghostbusters this Halloween.
Super Casual: Ghostbusters “ROOKIE” Uniform Tee ($15)

This tee is available online @ Hot Topic for $15. It is similar to the glow-in-the-dark Venkman uniform tee, which is also available. Take note, the Venkman tee glows in the dark, but it doesn’t have the proton pack printed on the back.
Casual: Ghostbusters Uniform w/ Inflatable Proton Pack ($25 - $40)

The Ghostbusters costume with inflatable proton pack is the perfect option for fans who are willing to kick it up a notch and cross the streams. Available in kids and adult sizes, you can find this costume in most retail stores including Target and Walmart.
DIY / Hardcore Fan: Ghostbusters Flightsuit /w “real” Proton Pack ($100 - $1000)

Last, but certainly not least, you can re-create the real thing with a little blood sweat and tears (and some cold hard cash as the offset). You can go all in and download plans to assemble your own proton pack and Ghostbusters flight suit like Egon Spengler himself. Alternatively you can gather patches, flight suits, proton packs, and other props on Ebay.
Big ups to Proton Charging for inspiring this updated version of the classic Ghostbusters costume - cheap and easy post from 2005. Use your imagination and have a Happy Halloween!