Might be coming into owning an iPhone 3GS soon. Cosmetically, it's a nightmare. The on/off button is missing, and the volume buttons are missing. The back plate is cracks, and the screen looks really dirty with heavy abrasions over it all. My question, am I able to replace all this so that it looks new again? How much will this end up costing me? If i buy a new screen + back plate off eBay, will this include power buttons/mute switch/volume buttons? Thanks in advance!