www.pod0 :
I've got a shitty i5-2400 with radeon r7 and a 250gb hard drive and im living with it for 3 years almost
It was enough for me to run games like cs:go, lol and really shitty graphics fortnite. Now I want to play pubg and this crap can't run it. So i think i can live with 480gb
brace yourself: my rig is 8 years old
AMD 955 black at stock circa 2009
HD 7950 3GB circa 2012 replaced the hd 6970 2GB
8GB DDR3 1600 dual channel. circa 2008
SSD's and HDD's
I would think the GPU is the limiting factor to playing pubg. I play it fairly well, I have capped the FPS to 75, settings at low. when I play I am usually watching a movie on my other screen, the effect is play the game deaf. but my old a$$ rig can play so should yours with a tweak or two. if you can replace the GPU and PSU and add an SSD
if you could get a 1060 and the SSD with a new PSU, you should have enough to play what you want for a while longer, then you can replace the trinity (CPU, RAM, motherboard) as they will need to be replaced together
all advice is assuming a 1080 resolution. higher will need more firepower
which r7 is it?