Apple is dropping the price on older models of its iPhone as it prepares to release the new iPhone 12, 12 mini, 12 Pro and 12 Pro Max. Apple is also ending sales of the iPhone 11 Pro.

All that means prices of some iPhones are coming down while the iPhone 11 Pro might see a price increase since you'll only be able to find it in leftover inventory at carriers and at third-party sales sites such as Facebook Marketplace, Gazelle, Craigslist, and Amazon.

You can take advantage of new phone releases by buying last year's model or the year before that. The iPhone X and Xs are great phones and will be plenty for average users.

If you're looking to upgrade, what can you do with your old iPhone and get the most value by trading or selling it?

All the major carriers and Apple allow you to trade in your old phone. You won't get cash, but you will get the trade-in value applied to your monthly bill. The most popular smartphone now, the iPhone 11, has a value of $100 at Apple, provided it works.

Verizon says a Samsung Galaxy S9 has a trade-in value of $550 but the street value is just $100, which will be applied to purchasing the latest Galaxy s20. By trading it in, monthly payments on a new phone will be $6 less. Other carriers offer similar deals.

If your phone is 4-6 years old, trading it in will save less than $10 a month on your bill.

You might get more if you buy or sell on Craigslist or Facebook Marketplace. I found iPhone 11s on Craigslist selling for about $200-$500, depending on storage while iPhone 7's typically sell for under $200.

Companies such as Gazelle.com offer cash for old smartphones, but you won't get as much for one as you would by selling it yourself. An iPhone 7 in good condition with light signs of use is worth $58, paid in cash. A Samsung Galaxy 9 is $99.

Before you trade or sell a phone, back it up to save all your photos. Download Google Photos and save them in the cloud. After that's done, go to settings and general. and erase all content and settings. This cannot be undone, so back up the phone before confirming the reset.

If you're buying a phone off Craigslist or Facebook, have the seller meet you at your wireless carrier to make sure it works and that it hasn't been reported stolen. If an iPhone is reported stolen, carriers can not activate it and you won't be able to use it.