Gazelle wants old iPhones and they are willing to pay top dollar for them. The trade-in website is promising to pay more for old iPhones than other competitors from now until Sept. 9 when Apple is expected to introduce a brand new iPhone, CNET reports.

The Gazelle promotion promises to beat wireless carriers' offers on iPhone trade-ins as well as the price that Apple will pay for the devices. The deal assumes that customers will stick with their same carriers when upgrading to a new iPhone and trading in their old device.

The deal from Gazelle shows the demand for the latest technology. Customers who always want the newest phones typically purchase the phones right when they come out and they have to find something to do with their old phone.

With new policies from wireless carriers like eliminating phone subsidies, customers are now seeing how much these smartphones actually cost. To overcome the sticker shock of these smartphones, customers hope to get as much value from their phone trade-ins as possible.

Gazelle's promotion is simple, the company will offer customers $1 more than their carrier or Apple will offer them for their iPhone 5s, iPhone 6 or iPhone 6 Plus. Customers will have to show proof of the trade-in deal offered from their carrier or Apple by sending an email to Gazelle. They will also have to show Gazelle the amount that their carrier or Apple quoted them for their trade-in.

Carriers usually give trade-ins for old phones by offering a credit, but Gazelle will give their trade-in customers a check, Amazon gift card or PayPal credit.

Gazelle will only compete with wireless carriers or Apple and not with other third party websites like Amazon, Nextworth.com or CashforiPhones.com.

Customers might be able to get more money by selling their phones by themselves on Amazon or eBay, but if they are in a hurry to sell their phones in order to get the brand new iPhone right when it comes out, this Gazelle deal seems like the best option.