Customers who switch to Sprint Corp from Verizon, AT&T and T-Mobile will have to pay only half of what they pay for their existing plans, the No.4 U.S. carrier said in a bid to lure users to its network ahead of the holiday season. Shares of the company, which is in the middle of a turnaround plan and has vowed to cut over $2 billion in costs by the end of 2016, were down about 8.4 percent in afternoon trading.