I heard about this a while back and was thinking of adding to my Picade. I know Micro SD cards are cheaper now but 314GB is 314GB and 1Tb is 1TB. That is alot of Dreamcast, PSX, and PSP games. Check it out and share your thoughts.
WD PiDrive 314GB $32.00
Pi 1TB of HDD storage $79.99
Check this video out. Once setup all you have to do is change the rom directories for each emulator on Retropie.
Raspberry Pi (Nin10do Lite V2 console