People buying a new iPhone are being warned they could waste thousands on one costly mistake

The iPhone Duo is now officially out in the wild, and despite a pretty sizeable price tag, many rushed out on Friday to pick up the new smartphone.

Apple's first folding phone is available for $1,999, with consumers warned they could be left empty-handed due to limited stock of the new device.

For those considering purchasing the iPhone Duo, an expert has issued a warning regarding how you go about buying the phone as a simple mistake could cost you thousands.

There's no doubt that forking out close to $2,000 is a lot of money in one go, but if you decide to purchase the latest iPhone on a carrier plan, you will be paying a lot more in the long run.

Philip Stoelman, CEO & Founder of Network Republic, told UNILAD: "When you walk into a carrier store, the phone looks cheap.

The Duo is Apple's first folding phone(Annice Lyn/Getty Images)

"The carrier spread the cost of the phone over 36 months of monthly payments. The best deals (i.e. lowest monthly payments) are typically offered with the most expensive unlimited plans.

"Thus, in reality, you’re paying for the phone through your plan."

Stoleman added: "What people don’t realize is that the low monthly cost to use a phone over 3 years hides the true cost of the device and then the cost to use it over the term of the contract, including any additional fees.

"A new iPhone 18 Pro currently starts at $1,199 / 399 $ for the 64GB / 256GB models from the Apple Shop. The cost of owning an iPhone over a carrier contract actually exceeds this figure after you factor in the cost of the contract that you are locked into for 3 years."

So, it's important consumers consider a number of factors before committing to a plan with a carrier, the expert has warned.

iPhone Duo released on Friday (Ming Yeung/Getty Images)

He added: "First, figure out the total cost of the device and then compare the total cost to the monthly cost to you of the service. The way that carriers market their plans is around the monthly cost to you.

"You should ask the store exactly how any promotional credits will be applied if you change carrier in month 12 or 24. Make sure this is confirmed in writing.

"In theory we should all plan our device upgrades over a number of years and then calculate the lowest total cost of ownership for the full period.

"If you keep a phone or laptop for 4 years then a 36 month contract on a top tier tariff is likely to cost more in the long run than a lower tariff with a longer contract."