The official source currently lists the PC Game Mortal Kombat 1+2+3 for $5.99.
If you are looking to purchase the digital activation key, several options are available: Mortal Kombat 1 2 3 Free Download (GOG)
Offers the Mortal Kombat 1+2+3 EN Global GOG Digital Activation Key for approximately $2.58. The official source currently lists the PC Game
Introduced the Shaolin tournament where seven fighters, including Liu Kang and Scorpion, battle to save Earth Realm. including Liu Kang and Scorpion
Added a "Run" button, "Dial-a-Combo" attacks, and new fighters, though it famously excluded Scorpion until later updates. GOG Availability and Features
The bundle brings the bloodiest arcade classics to modern PCs. Originally released between 1992 and 1995, these titles defined the fighting genre with digitized graphics and "Fatality" finishing moves.
Another marketplace for purchasing the Mortal Kombat 1+2+3 GOG CD Key.