You can get practically the same hard drive from cheaper if you buy it in the casing and just take it out yourself.
http://www.amazon.com/gp/aw/d/B00TKFEE5S/ref=mp_s_a_1_4?qid=1452460573&sr=8-4&pi=AC_SX110_SY165_QL70&keywords=seagate+2tb&dpPl=1&dpID=41ONsZtUWKL&ref=plSrch
This is the one I used. The hardest part was getting it out the caddy, but after that, it's simple. It also gives you the caddy to store and use your old ps4 hard drive too.
There's a video and lots of information here:
http://www.eurogamer.net/articles/digitalfoundry-2014-how-to-cheaply-upgrade-your-ps4-to-2tb
I will try and find the tutorial I used to wipe the old hard drive for use on a PC too
the only real difference between two of the same hard drives as external vs internal is the firmware used in the drives might be of a different date(newer vs older). literally the only difference.
you can ghetto rig any playstation (or PC if you need space there) with a Sata extender cable and any drive loaded with the PS4 firmware for console use.SSD, SSHD(no point in these), HDD.
[spoiler]an SSHD is literally just a normal HDD with an upgraded/bigger buffer cache.[/spoiler]