weatherproofing old double hung windows

Stoopsitter, I bought several Indows. https://indowwindows.com. They are a bit unwieldy but if you are ok with not opening some windows, they are great. You don’t even notice that they are there. If I remember correctly a rough townhouse window ran about $400 a piece. The inserts really cut down on cold drafts and noise. They saved me when my heat went out and my plumber was a no show during that cold spell in 2017.