New iphone 3gs received today. These are going for 500-600 bucks right now on ebay. Seriously thinking about selling 3gs on ebay to make a quick profit. My plan is to use my wife's upgrade eligibility to get a 3gs when they are back in stock and just stick with my 1st gen iphone for a bit longer. I would prefer not to open the new phone if I decide to list on ebay. However, if I list on ebay, do I need to remove the sim card that came with the new iphone 3gs? Is this new sim card associated with my phone number somehow? This phone was purchased through att.com as an upgrade to my 1st gen iphone.