You can now purchase Konami’s Metal Gear Solid V: Ground Zeroes for only $20.
That is, if you want to buy a boxed copy of Ground Zeroes as the digital version still retails at $30 for the current generation versions (Xbox One and PS4). The previous generation consoles, PS3 and Xbox 360, both sit at $20 for the boxed and digital versions of Metal Gear Solid V: Ground Zeroes.
There is also a PC version for Ground Zeroes coming to Steam in December which supports in 4K resolution.
Metal Gear Solid V: Ground Zeroes is the prologue to Metal Gear Solid V: Phantom Pain.