The main area in which I think for-profit dealers can
contribute would be
in a grading system and price guides, something that is interesting to all
collectors, even if they have no plans to sell.
I agree. Insurance companies like to put value on things, and currently
this is very difficult for me to do with my collection at the moment.
There are a few items which I might be able to take a guess at, but for
the majority there is no 'market value'
--
Kevan
Collector of old computers:
http://www.heydon.org/kevan/collection/