Up to now I've always gotten a new phone from the carrier in exchange for signing a new 2 year contract. As I don't want to get rid of unlimited data I am now looking at getting a used S4 to replace my Rezound. I have been watching Swappa and see that there is apparently some level of protection as the seller has to input a clean ESN into the system in order to sell. I do not plan on buying an unlocked phone either. is there anything else I should watch for when looking at a listing? I need to make sure the phone will run on VZW 4G LTE. Also, when a new model comes out, such as the S5, what generally happens with the price of the one generation old phones? In the last month I've watched the prices drop a fair amount. they are now hovering around $310-$340 for a good condition used one with some going lower and some higher. I'm hoping to grab a phone in about a month or less. Wondering if I could expect prices to continue to fall into the mid to high $200s?