You do also need the Mongoose Traveller 2E Core Rules if you don't have them. You can save a little scratch by buying the digest-sized Pocket Edition. It is a little harder to read on my own aging eyes and it's softcover, but does contain the 2022 Update (preferred, current rules).

Good shout, hadn't realised.

a man is standing in front of a window holding a remote control in his hand .

ALT: a man is standing in front of a window holding a remote control in his hand .

But really the price savings isn't huge, just make sure to get the 2022 Update, it's the complete core. If you are going to be running, hold off on getting Bayern & get Ships of Frontier (70 ships) or Vehicles of Frontier (over 100 vehicles) to take care of those pesky GM details for you and players