I've gone past these money spinners... but if one has the cash, by all means.
As you know Ian it can be an expensive interest or hobby collecting rock music records and cds or at least it can be if like me I have around 20 rock and blues/rock bands that I like and were active from the late 1960s and into the 1970s so with those particular bands I usually always have to collect the bands entire collection of officially released studio and live albums and in the last 20 years it's become normal for bands and artists to release 'bootleg recordings' officially as well which means MORE MONEY spent!.
I few of my favourites-
1.Taste/Rory Gallagher everything
2.Thin Lizzy everything
3.Led Zeppelin everything
4.Mountain 1970s & 1980s
5.Wishbone Ash 1970s & 1980s
6.Deep Purple the 1970s era in particular
7.Johnny Winter the 1970s era in particular
9.Baker Gurvitz Army 1974-1976
10.Love/Arthur Lee 1968-1974 in particular