Earlier this month, I purchased an used BlackBerry Curve 8310 (AT&T Wireless) from a friend. It's about a year old, has some scratches and is out-of-warranty. I paid $45 for it. Since then, I've added a 2GB MicroSD card ($10), a silicone case ($3) and a screen protector ($1). I've also upgraded the O/S to the latest version. Today, another friend has expressed interest in purchasing it from me. I want to make a slight profit on this sale. Does anyone know how much this BlackBerry is worth? Thanks.