Good Q!! (We also put ours off for awhile, until my wife put her foot down!)

I would say first to try and get a few quotes (3-5 if you are up for it). Try to get a an estimate for the same type of window (sometimes there are multiple levels and it’s best to try to get an apples to apples comparison).

A lot of companies will do replacement/retrofits - that’s what we did at our house last year - which was much more reasonable than doing all brand new windows. You lose a little bit of the window due to the new frame that is put in but it wasn’t deal breaker for us.

Good luck on the window hunt!