My reasoning - as you will see - is that collectors are much more systematic, exhaustive, thorough and consistent in their collecting. Whereas I will only pick up things that have some specific use for me.
Specifically, I don't go chasing after special editions of books I already have a version of. So, for example, I'm not particularly drawn to those Folio Society editions of Bradbury books.
But what I do go after are one-offs, like It Came From Outer Space - which presents Bradbury's original typescript for that film's treatment.
And I do have a few magazines, including a grand total of three - count 'em, three! - pulp magazines. Watch the video, and I'll show you a couple of them.