Which approach is better? The house is 45 year old, in a northern climate.
anderson windows and doors
I did my own windows on a house built in the early 50s so we are about the same. Two of my neighbors did inserts, I did the full job, the store called it new construction windows. The inserts are cheap and dirty and both of my neighbors have approached me about sealing their windows. They tell me that between them they don’t have one window that isn’t drafty. I strongly recommend you do it right the first time. Get a second and maybe even a third bid on the full frame deal and be ready to not have it all done in a couple of hours. Shouldn’t take more than a couple of days though.
I have been told you may or you may not get what you pay for but you will damn sure pay for what you get.