If this doesn't pan out, it looks like http://teespring.com/ is a good alternative to taking care of everything in one go. As far as I can tell, you could set the minimum to be as low as 10 shirts and they'd still cost under $20 per.
I'll make sure we look at that since the outlook for the fundraising is pretty grim currently. We're all pretty bummed that this doesn't look like it will make it in this iteration. We really want to get it done so we can share something as a Giant Bomb community and give the staff some shirts as a thank you for all they do, especially bringing us together since a lot of us all joined up after the fanfest coverage last year.
What's the deal with the two S-XL (Rest of the World) at $30 perks? They are worded differently, but seem to be the same thing.
They may very well be the same thing. It is possible it is just a mistake made by the creator. I'll see if I can draw his attention to it and get a response for you.