I also like the ideas of the packs. As a member who has been a part of quite a few coops, I could see this work in conjunction with the coop. You have kits pre-made at your leisure that members could buy at a set cost. Co-Op Managers would still do "kits" for new stuff or old stuff when the need is there (representing a cost savings), but for those of us just needing some extra PCBs, it would allow us the flexibility to get them when needed. If we have to buy 3 boards just because we wanted one, we could always post the other two up for sale and handle it independent of the time it would take you to satisfy two members. I've went in with another member to get CG-1500 enclosures and it worked out great for both of us.
I would definitely switch over to flat rate shipping on everything. It would make it so much easier on you. We are all appreciative of your efforts in making DLA a success and DIY fun. We want you to enjoy it, and not be stressed.