My parents replaced windows with BF Rich Horizon windows with Tuff-Glass (which is the sound reduction feature). They’re pretty basic windows. The sound reduction glass cost about $100 more per window. My dad installed the windows himself, so the costs are very different, but for that level for just the parts buying from his local distributer, it was $240/window. Obviously, the installation is a really important part–if they’re not installed properly, sound and air will get in around the frame of the window, but they’re happy with the product.