As I have said, if you can teach someone the rules for grading, why should they have to be part of a business to be certified? There is no reason. Qualified is quailified. Annual cost for a stamp? I'm sure it's reasoned that those fees maintain the "standards organization". With the expertise and experience of certain guild memebers and already being an established organization(and we already pay dues to maintian the organization), it is likely feasable that they could maintain and administer the standards for grading and selection. They'd have to vote as to whether that is something they'd want to take on.
I also understand it is desireable to maintain some sort of control of stamps. What is a stamp? It's a mark that denotes that the person has been trained and passed minimum grading standards. Each stamp should show the organization as well as a number that designates who's stamp it is. It should also be required that training be renewed at some interval(like a driver's license). Each owner of a stamp is responsible for their own stamp. If it's misused, the individual should be liable, not the organization. The organization can only assure standard rules, training, and administration of testing.
Once again, the point is to allow hobbyists or others doing timberframing on a small scale or small scale sawing operation, to grade their own stuff or for friends or to be available locally to help other guild members. Certification should also be verifiable online - a building inspector could look up the stamp number and verify that it is current, valid, and contact info for the grader is available.
One example is UL. UL is a recognized standards organization. They also have to certify products which leaves some companies hostage to their schedule, fees etc. Other standards orgs have popped up to combat this, like CSA.