3% or higher would net someone (with great credit) a free or nearly free refi to a lower rate. If they are better off doing so or not would be situational. I should clarify "wasting money" maybe like wasting money changing your oil too soon. You may have good reasons to do so.
Interesting thought process. My credit union doesn’t offer free refi transactions. My credit score is over 800 and I still pay about $2k. Maybe it’s my bank IDK…
just my $0.02