Save your game and wait until the soldiers got rid off the stalkers and speak to the soldier towards the left of the bridge (close to the debris, not the one at the campfire!). Once you have the silenced handgun and ~500 RU you should make your way north towards the bridge where you can see 4 or 5 army soldiers engaged with a few stalkers. At that point you should already be able to but the silenced handgun and have some spare change (ideally just over 500 RU), if not then do a side-mission for the stalker you just saved. Go back to the camp you begin the game and sell the collected guns. Play the first mission (rescue a stalker from some raiders) and collect as many items as you can from the fallen.
