Not too sure (in my own opinion) about experienced HD vendors being interested in a trade association. Apparently they are a pretty independent strain of people. Take a look at how dead this board has been lately with few of the established folks sticking around posting new threads or offering help. Not at all like some of the window cleaning or power washing sites I used to belong to.
I would think that to establish a new association you might want to use a lower price to entice new members and try to build a large membership. Myself, not knowing about this group, the thing that sticks out to me is that one of the guys organizing the group marks up chip clips and dog sleds about 400%. Not saying he isn’t a good guy.