Why does it say va'Ya'anu and also Leimor?
Ohr ha'Chayim #1: Many people do not speak at once. One spoke on behalf of all of them.
Ohr ha'Chayim #2: This teaches that they did not agree like they said initially. In the end, [Efron] demanded the full price.
Ha'Emek Davar: They resolved what to answer, and sent one of them to tell him their answer.