Do you have a sense on how bad the increased cost is for reasonable sound isolation (talking/tv not garage band)? Because I have dealt with loud neighbors, and

Do you have a sense on how bad the increased cost is for reasonable sound isolation (talking/tv not garage band)? Because I have dealt with loud neighbors, and if the problem could be ameliorated for an extra $1/m or something else trivial, I will be enraged that it is not mandated everywhere.