I bought a stack of 1TB External HDDs on clearance at Target last year, I think at this point I have 1 hard drive left. 1 for my Xbone, 1 for my PS4, 1 for my 360, 1 for my Wii U, 1 for movies and work and such, and I was setting one up for my hacked Wii because my previous external was acting up, but it wouldn't play my gamecube backups... and my old drive stopped acting up, so now it's just sitting there for me to figure out what to do with. I ripped one open and put the 1 TB drive into my BC PS3 shortly before it went YLOD. I still need to try to repair it or pay someone to do it.
Spent about $20 a drive... but they should suffice all around.