I think anything people will plunk down money for, is. Further more we have a variance on what a box set is. For LLLR for example, it's six or more CD's (according to MV).
And then of course we have to judge it by the music. So far it appears the argument is fame, Trek, M:I, etc. Can we just buy something and enjoy it regardless of whether it's known and a box?
Is there any chance we could keep all discussion regarding the Mission music for the original TV series in the other dedicated thread called Mission Impossible (TV) 6CD?