Nice! These posts gave me an idea for easily purging huge amounts of duplicates. (1100+ in my case)
What I did:
Created a new, normal, temporary playlist
Went to the music library, hit Alt+E to bring up the Tag Manager and selected only "Duplicate Files"
Copied ALL the files listed here into the temporary playlist
Back in the Tag Manager for the entire library, I selected "filter: Custom Filter" and entered the following criteria:
Playlist IS [Temporary playlist name]
Filename ENDS WITH _1.mp3
Then I just deleted all of these.
There are a couple of caveats:
It only works when MusicBee is organizing all the files automatically, and in a way that they would be in the same folder and filename.
This only works if the duplicates have the same file extension.
This would really suck if the song's name literally ended with "_1"
Of course it goes without saying that one would only do this at their own risk...