Spend 2000 dollars at vending machines.
It is rather self explanatory. You may get it by the end of the game, you may not. It depends on how much you go to vending machines and if you hack them.
If you're just going for the achievement, don't bother hacking the machines. Just go ahead and buy them at regular price.
If you like hacking, well, good on ya. Just be sure to buy often and you'll hit it.
Even then, you don't need to not hack. I hit it by hacking long before the end of the game. Although I also buy things quite often....