I keep boxes if it is required for a return or warranty repair/replacement or if it is recommended to or safer to transport in the original box....
I still have all of the boxes for every part I bought for my first pc build, every cell phone I've had the last 8 years, both of my mechs, every digital camera, my 65" TV, ps3, Wii, etc....
I haven't really bought alot of vape gear that came in boxes worth keeping....