For a brief moment T-Mobile (NASDAQ:TMUS) had taken the lead when it came to offering the cheapest way to get your hands on an iPhone 6s. That ended quickly when Sprint (NYSE:S) one-upped its rival's low-cost lease deal with one of its own.

It's a rapidly escalating war between the two carriers with the clear winner being consumers. Both companies are offering cheap prices and while Sprint has a cheaper deal, it's being offered to a more narrow audience so it's worth considering what each company has to offer. 

A look at T-Mobile's deal
When the new iPhone was first announced T-Mobile initially offered a $20-a-month-for-18-months lease on Apple's (NASDAQ:AAPL) latest phone, with the customer being able to buy it outright at the end of the term for $164, bringing the total cost to $524, well less than the full retail price of $649. People who opt for this plan also get the company's Jump! On Demand, which allows them to switch phones with no penalty -- though the price could change depending upon the device -- up to three times a year.

Now, for a limited time, it's offering consumers the same lease on an iPhone 6s with Jump! On Demand for as low as $5 a month, as long as they have a device that they own outright to trade in. The higher-end the trade-in, the less the customer will pay.

The company is only offering the $5 price for people trading in the previous iPhone model, as well as some flagship phones from Samsung's (NASDAQOTH:SSNLF) line. Still, slightly older phones can get $10 a month pricing, and pretty much any reasonable trade-in brings an offer of $15 a month pricing.

T-Mobile laid it all out in a fairly simple chart:

Source: T-Mobile.

"With these incredible $5 and $10 a month deals, we're giving customers just one more reason to come to T-Mobile," said CEO John Legere in a press release after he introduced the new plans in a Periscope video. "This is a deal that only the Un-carrier could create, let alone make into a reality -- and the crazy demand we're already seeing tells me the carriers' customers just aren't buying their BS anymore. For your new iPhone, the choice couldn't be clearer."

Legere can sometimes come off a bit cartoonish -- like a pro wrestling manager hyping up a match. In this case, his bravado is backed up by the offer.

What is Sprint offering?
Sprint's new lease offer as part if its iPhone Forever program lets customers who have an iPhone 6 which they own outright to trade it in in exchange for leasing the new phone for $1 a month. The carrier will also offer a $10/month price on iPhone 6s 16GB with the trade-in of an iPhone 5s.

That's a bold pricing offer as well, but it's more limited than the T-Mobile deal since it only covers Apple's latest two models while T-Mobile extends across the handset universe. Like Legere, Sprint CEO Marcelo Claure is pretty proud of himself.

"Once again it is clear that the best place to get the new iPhone 6s and iPhone 6s Plus is Sprint," said Claure in a press release. "New and existing customers who trade in their current iPhone 6 can now get a device for only $1/month, making it the best way to get the iPhone – and a yearly upgrade is included in this charge. We are certain that more people will continue to switch to Sprint because of the great service and value we offer."

Both companies are requiring customers to go to their retail stores to claim these deals.

Which deal is better?
Sprint and T-Mobile are both offering pretty compelling deals on their new phones. Claure's company is offering a lower monthly lease price on the phone and iPhone Forever limits people to upgrading to the latest iPhone. T-Mobile's offer costs more but Jump! On Demand customers can trade in their handset up to three times a year with no penalty.

These are both good deals and while Sprint can claim it has the cheapest iPhone offer, T-Mobile's lowest-price is accessible to more people and it offers more flexibility. In either case consumers will be saving a lot of money over the roughly $27 per month cost to pay for the phone on an installment plan. They will also have the ability to upgrade to at least the next iPhone (Sprint) or any phone they want multiple times a year (T-Mobile).

Daniel Kline owns shares of Apple. He did not have a trade-in, but did switch to T-Mobile. The Motley Fool owns and recommends Apple. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.