Update: Their live chat system works, I spoke with a rep, and ordered a couple. Custom cables with mini-b connectors were only $1 than the premade ones with micro-b connectors, presumably because they are making the coiled cables themselves anyway. Note: Custom orders have to be done with a credit card over the phone, their website doesn't have a way to handle them.
I also asked her about pricing tiers for bulk orders, and she is sending me that info via email. If it seems feasible, I'll set up an IC.