Dick, I'm not a collector, I don't have any feedback for you from that viewpoint.   

My ancestors 'got collected'.   The recordings were stowed away, poorly indexed and deteriorating, in distant and obscure places where only 'scholars' could access them (or the public at great expense and hassle).

So my ethical problem is when collectors 'save' material from the last living exponents of it, then hide it away from the local community. (Yes, I know, the sources should have passed it on to the children but many were tone deaf and working two jobs and didn't realize how quickly the stuff would get lost--after all, someone had come along and 'saved' it.)

If you're going to collect, do you not have a responsibility to leave copies in the local library rather than hauling the only copies to the capital city? Isn't this duplication and archiving where some grant monies should go, rather than piling up endless one-copy central collections no one ever sees, or to publishing abridged selections by later researchers?