Detect Duplicate File before it's Written to disk?

For a later revision, if it’s possible to detect if there is already a track named <track.mp3>, BEFORE it saves as /3TB/MBP Sorted/Artists/Album/Folder<track.01.mp3>, so I can instead do
/3TB/MBP Sorted/Artists/Album/Folder.01/<track.mp3> instead, using the normal increment filename routine.

Instead of incriminating the track name, I want to increment at the level prior. This would place duplicates in a subsequent directory instead.