I've thought the same thing before. But looking at the prices of the game online (below 20 euros), it gives a lower entry point to the series great JD2 - just under JD. So new players can jump directly to the sequel through this bonus track discs.
Either way, they've put too many of these games out. I know in this house we won't be buying this bonus track version or JD3 unless you can import the songs.







