I think you're seriously underestimating the cost of redoing insulation. If you have an unfinished attic and your walls are fine, then yeah, laying down some ne

I think you're seriously underestimating the cost of redoing insulation. If you have an unfinished attic and your walls are fine, then yeah, laying down some new fiberglass is easy, but otherwise, it basically requires gutting all the walls and top floor ceilings. The cost (here anyway) is significantly more than $4k, and the disruption to daily life will make it feel double.