The thing is, from what I understand, Radioshack never cleared them out. They might have them for that price. That would be funny.
Or did HP recall the tablets or make the retailers sell them?
I know Costco just slapped their pallets of Touchpads on a truck and sent them back to HP, as did many other retailers, so Radioshack may have done the same. I think it was up to the retailer if they wanted to deal with the markdown (and associated hordes of customers) or if they wanted to just do an RTV.