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PSA – 2TB Samsung 2.5 inch Hard Drive PS3/PS4 compatible coming 31 March – £149.99(r/PS4)
You can just get one of the Seagate Backup Plus Slim 2TB (Amazon Link) and take off the housing, that’s what I did. It has the same Samsung M9T drive inside. I paid $129.99 last week for it, works flawlessly.
Plus, if you don’t destroy the housing when taking it off, you can put the 500GB from the PS4 into the Seagate enclosure and have an extra 500GB portable hard drive.
Edit: Amazon.co.uk doesn’t appear to have the Seagate drive in 2TB, but I’m sure you can find it somewhere across the pond.