Unfortunately greed once again rears its yapping head. I would advise against it even for the most rabid completists. Motörhead have no control over what's done with these early songs, and don't want fans to think that the band is involved in putting out such a costly box set.
Elvis Costello was similarly critical of a deluxe package issued by his label, for many of the same reasons. The conflicts highlight the fractured ownership that band's have of their early catalogues, and how labels rarely need permission to issue these types of compilations.
That said, it is a pretty impressive looking set.