It’s different with unified memory.

Utilization doesn’t matter, unused RAM is wasted RAM and macOS will use all available memory to give the user a snappier performance. Only consider more RAM IF you see red memory pressure graph or experience any hickups and slowdowns in your workflow.

bhphotovideo deal for $2799? This is tempting af tbh, you won’t get M3 machined specced anywhere near that for this money.