Traditional online trade-inOnline resellers like Gazelle and NextWorth offer a good, straightforward way to get some money for your current device. The two tend to offer more or less the same price for phones, with NextWorth edging out Gazelle by a few bucks — for instance, $302 for a 16 GB iPhone 5S compared with $295 on Gazelle.
More money — maybeIf you're feeling a little more adventurous, you can try Glyde. This service lets you set your own price, but they don't guarantee the phone will sell any time soon. It might be tomorrow, might be in a week — might be never if you ask for too much. But you might get a good $20 or $30 more than if you used the other services.
Ebay, too, offers a phone-selling option that lets you set your own price, and you might be able to get even more cash that way — assuming it sells. There's no shortage of used iPhones on the auction site, and they're priced to move. Amazon does something similar, with expedited processing if you take a gift card for the site instead of cash.
Not pre-sold on the new iPhone?Waiting to see what Apple has in store is a perfectly reasonable option too. After all, if you sell your phone today and the iPhone 6 isn't that exciting, or you don't like the design, you're stuck. If you don't mind losing out on the best price for your current device, there will likely be some good options for a limited-time after the announcement.
Carriers will almost certainly announce promotional terms for trade-ins where you can get more than your money's worth for an older device. Something like a guaranteed $200 credit for any smartphone could be a good option if your phone would normally fetch half that. And, of course, if the new iPhone doesn't pique your fancy, models like the 5S will be getting steep discounts after the announcement.
Need the money in a hurry?Impatient? Call up your local Best Buy or Radio Shack and see if they have an automated trade-in machine or an expedited phone reselling process. You won't get as much as you will from any of the above methods, but it's cash in hand within the hour. And then there's always Craigslist.
One last thing: Before you sell, make sure your phone is unlocked! This simple process lets your phone work on other networks, but you'll need your current carrier's help to do it. Call up customer service or drop by the local store — as long as you own your phone (that is, you're not still making payments on it), they should be willing to do it. Some services won't take phones that are still locked to a carrier, and some will pay less — so make sure.