A big part of that was the GC adapter though... since getting that standalone was difficult enough (it was going for $80 alone at one point) so spending $50-60 over MSRP on the CE made (which was $100, I think?) for the game + controller make a lot more sense than spending $50-60 more on just the adapter.
I think there's a chance this'll stay in stock. Nintendo CE's don't last too long ever but when you compare the Wii U's holiday offerings (Xeno X, AC) to that of the PS4/X1's (major 3rd party releases, like Fallout, CoD and Battlefront), I would think the last thing Nintendo wants is to shortages. Plus, I think more and more people are realizing that this CE sucks. Other Nintendo CEs have been great values (i.e., Wind Waker HD and MM 3D both threw in a figure for $10 more) but this one just doesn't seem worth it to me. Plus, I'm sure NoA is kicking themselves for missing out for bringing the original over on their own, instead having to share profits with GS.