Will a dampener help distribute air more evenly?

Question

lot of cold air to the back of house, living room and kitchen dont get alot of air flow. a.c. guy says putting a dampener in will help and new registers in each room and seal up the duct work for $475

Answer 1

i agree with charlie. the price they are quoting sounds fair but get it in writing

Answer 2

Its a damper and it should work also ask about a booster fan.