Where is the best place to trade in my 4S?

[iMore Question]

where is the best place to trade in my 4s (ecellent condition) when I want to buy the 6

 

[phreddyl]

I use craigs list- You have to weed through the shady characters who want you to ship it to their second cousin who is overseas... Have the person meet you at the carrier store- if they wont then dont do the deal