CBS said Thursday it has sold between $2.5 billion and $2.6 billion in upfront advertising commitments, up from $2.3 billion last year. Joann Ross, CBS president of ad sales, said she was virtually done making deals and that the network was getting cost-per-thousand increases in the 4 percent to 6 percent range, similar to the range achieved by ABC. “Clients were willing to pay for our good schedule, but the market may end up being a bit lower,” she said.