Go to the junk store in Scrap and agree to pay the 300 credits to search for 3 items. After doing this, talk to the owners again and pick Selling, then go to the bottom selection (Hyperion Bazooka I believe) and press Circle 2 times. Then hit cancel and go into the room with the junk, you'll be able to get 7 items instead of 3. After picking 7 items, talk to the owners agian, hit selling, highlight circle on Hyperion Bazooka and hit circle twice. You can do this as many times as you like. It's great for getting cheap armor early on in the game.