First off Michael and Robert....Great meeting and talking with you at the Blade show! It was so great to put names and faces together!
Now, on to the meat of the question. Many buyers of custom blades see membershiip in a recognized organization as a commintment on the maker's part. That, in turn, will lend credibility and value to your work in the eyes of potential customers. Standards are also set for the organization, and peer pressure from within can be a powerful motivator to maintain quality! This is another area that customers see and recognize.
The ABS sets and maintains standards by the judging standards for Journeyman and Master smith ratings, and as an active member, there is always the inward thought of keeping up quality.
I am not a member fo the Guild, but do know that you must have the signature of 5 Guild members who have voting status in order to apply for membership. These signatures are not easily received, or lightly given since whoever signs is verifying on their reputation, that your work is of the highest standards.
A couple of other items on the Guild, you must attend the Guild show at least every other year, and must maintain current dues, Which I believe are substancially more than the ABS. A current Guild member can give you more complete, and perhaps more accurate information than I on the particulars.
I suppose the bottom line is that by belonging to an organization such as the ABS or the Guild, it shows the commitment to not only knifemaking, but to a certain standard.
------------------
Ed Caffrey
"The Montana Bladesmith"
www.caffreyknives.com