I ran the last O-ring GB, so feel free to reference the thread
HERE, as it has a lot of info regarding sizes or any other discussions. I closed it so it does not get bumped back, as that was a while ago.
I told many people I'd do a round 2 several months ago, but I simply got too busy with school, lab, and work. I'll follow through and do a round 2 this summer when I'm more free, so if no one else organizes the group buy by then, then I'll do it again. Here is some info and expectations just in case anyone else decides to run this. It only costs a normal stamp (45cents) to ship a full pack in a standard envelope, with the condition that you lay every single one out flat and put it inside a bag. Otherwise, if you just throw all of them inside an envelope, it will all bunch up and the thickness will be over 1/4", which is the max allowed thickness of a standard envelope. Any thicker than that and you risk the USPS machine tearing the envelopes or the employees returning the envelopes. If you're too lazy to package it this way, then it'll costs about $2 + material for shipping.
I ordered through Rubber Dynamics, the rep I got was Blanca. She's not the most accommodating person to deal with, and quotes I got were very inconsistent. Price ranged from 10cents to 20cents per O-ring, depending on size, material, and quantity. That GB had 8 different kinds to choose from. Everyone ordered at least one whole pack, and most also ordered a sample pack of the 8 different O-rings. I realized I was doing the $1 sample pack at a slight loss, and it was much too tedious to separately package them. So the labor is something to consider when packaging these O-rings.
Feel free to ask me any other specific questions or just reference the old O-ring GB.