Around the same time, Apple and wireless carriers began more aggressively promoting monthly payment plans. The plans have reduced the cost of a new iPhone to less than $40 a month from the $800 to $1,200 that customers had to pay upfront. The prices are lower for people who trade in used devices. The old iPhones, which could fetch up to $640, have been auctioned to buyers in Asia, who resell them at a markup, Maldonado said.
