A fully functional PS4 Jailbreak is now available for PS4 running on Firmware 1.76 or lower. The Jailbreak allows to run native code and/or Linux. All files for that exploit have been released here. As such, PS4 models running firmware 1.76 will probably skyrocket in prices very soon, and now might be the last time to get one at a reasonable price.
It’s easier to ensure you have the right firmware version if get the device new and sealed, not “used”
If you get a “used” console, be careful: most sellers update the console to the latest firmware before selling it. Ask them to confirm the firmware version before buying anything. This is true both online and in brick&mortar stores.
On Amazon and eBay, some sellers sell a different product than what the description says. I have seen some sellers offering the Star Wars bundle instead of the Killzone Shadow Fall bundle, for example. Be careful here, as always, ask the sellers for details if possible.
Amazon have a great return policy. Use it if the PS4 is not the one you expected!
Buying a PS4 new, with a guaranteed low firmware
The ideal way to get yourself an “old” PS4 firmware is to buy one of the old bundles, and to get it new. The ps3devwiki has a page listing these old bundles shipping with the old PS4 hardware, which are guaranteed to come with a firmware <= 1.76, if you buy them new.
“InFamous Second Son + Killzone Shadow Fall + Knack” Bundle – on Amazon
NBA 2K14 Bundle
FIFA 2K14 Bundle
Dynasty Warriors 7 bundle
Dynasty Warriors 8 bundle
Assassin’s Creed IV: Black Flag Bundle
Infamous: Second Son launch bundle
Destiny Bundle (black)
DriveClub Bundle (Black)
DriveClub Bundle (Glacier white)
Call of Duty: Ghost Bundle
Additionally, people are reporting that consoles bundled with The Last of us usually ship with firmware 1.76. Update: several people are reporting that there are 2 types of TLoU bundles, and some of them ship with firmware 2.03. Get confirmation from the seller before buying those!
If you know about other bundles that ship with a low firmware, please let us know in the comments section!