Good comments all. For a very nice summary Check out Les Robertson's book "Custom Knives Buying Guide" at
http://www.robertsoncustomcutlery.com/. It really answers this ? & a lot more. (This is not a paid advertisement!) I've been buying custom folders for about 7 years. My collection initially grew in # & now is growing in quality & shrinking in #. I recently read Les' book & even though I thought I understood what I wanted in my collection I learned a lot. It is an insightful, practical look at collecting custom knives.