How to Get the Wheeler-Dealer achievement in Metro 2033

Okay, so you've played through the whole game of Metro 2033 and feel like you've been missing out on something. Well, did you go after the achievements? If not, here's a tutorial on how to add some points to your gamerscore. The name of this achievement is called the Wheeler-Dealer. It's an easy to get achievement and requires you to buy and sell shotgun ammo over and over again until the achievement is unlocked. So good luck and enjoy!