I would say to people just keep on looking on all websites they can. Also maybe try contacting adafruit directly about it.
Today I managed to find a couple left on a Canadian website and grabbed them. Cost about 1 & 1/3 more and then there was the $6 in shipping (this is after converting the CAD to USD).
On a side note 3Derp, if you haven't noticed, I am finally putting one together soonish (I have like 3 projects I am currently working on, including upgrading my Christmas lights again, so it may be a little bit). Once I get really into into it, I will share with you how my alterations are going, adding the external USB ports as well as trying to add a battery indicator light.
I know it's been a while, but while I am at it are there any other alterations you would like me to see if I can manage? We already figured out that trying to get the analog controls working on the Pi's GPIO pins is possible, but with the parts/work needed, it is significantly more trouble than it is worth, so I don't plan to do that.