So, we have 3 phones on our family plan...2 iPHone 3G's and 1 Blackberry. My wife hates the blackberry so I'm thinking if I upgrade my phone I can give her my 3G and upgrade to a 3GS. I checked with AT&T and they said I was eligible for the upgrade. I'm thinking of getting the 3GS 16GB for $199. Can I sell the Blackberry on Ebay / Craigslist ....if so, what is it worth?