iPHONE 3GS NEEDED FOR £70 - £100 +

Hi there, Im looking for an iphone 3gs or better for around 70-100 and will pay cash on collection. The phone should prefferably be unlocked, but thats not essential, and should be in decent enough condition (not too many scratched on the screen, the back I dont mind) and should come with a charger. I look forward to hearing your offers and hope that we can do a good deal on this. Many thanks, Henry