For the achiement 'cash in' i was having problems in getting it. Whilst looking through forums i found other people with this problem. To get this to work for me is to go to the mission 'Mos Eisley Spaceport' ( sorry i am not so sure but i think its episode 2 to chapter 4 ) Drive your landspeeder to the door and get c3po to open it as usual, then build the at-st in the following space and blow up a blockade on your right upon entering this space. Get your landspeer and drive it into this new area. On the right there is a bill board inside its own little space. Once you are near the bill board park the landspeeder on the right hand side of this space which is the opposite side of this space to the bill board ( you may understand when you see it ). The Jawa will move painfully slowly towards the landspeeder, ignore all urges to kill him and let him crawl towards it, there should then be a cut scene and coins will drop on the floor.
Achievement done. Please reply to this to tell me if its any good thank you.