I've been offered my nieces Iphone 3 for £30, it's pretty old now and well used although it's been in a case most of it's life. The battery only holds a charge for about a day of use but I plan to replace it. Do these phones have a history of longevity?, I'm not bothered about speed as it's just supposed to be a reasonable upgrade for my wife who presently uses a god awful cheapo nokia. I just don't want to spend £30 on something that may conk out in 3 months. I know this is kind of asking how long is a piece of string but need some sort of idea if these phone wear well or not.