Hey. Welcome to the site Macca W. The release of 'Beatles - Rock Band' in '09 required the use of ALL the multi-track tapes at EMI. As a result, what usually happens when the vaults have been open for some reason, alternate tracks leak out into the bootleg market. In this case, many of the multi-tracks have individually leaked out. In '09 and '10 there were a series of 5 or 6 CD sets with all individual tracks for most albums, therefore enabling you to basically, create your own mix.
This set (and all the other albums in this series) seems to include 'new' mixes from those multi-tracks along with other assorted goodies (interviews/alternate takes/etc) in a lavishly packaged box set. This is truly 'bootlegging' at it's greediest. This was put together mainly to make money, although it seems that great thought went into what was put into the package, i.e. the 3D cover and the vinyl records.
Because we live in the age of lossless digital copying, the sound quality is likely near perfect.
What's it worth? basically whatever someone wants to pay for it. It's a pretty new series and the demand is not yet known so value is relative.
Hope that helps.
Friend: My favorite Beatles song is Band On The Run.
Me: It's not a Beatles song.
Friend: Wot! That guy, that guy, Paul McCartney sings it right?
Friend: Alright! That one is my favorite Beatle song.