When you are trying to build an Uber part, some times you have to use components that are NOT wildely available. With the price of this thing, it IS a limited video card. Heck, the "performance" video card market is a tiny part of the whole video card market anyway. Something like the 512 is a tiny part of that tiny part. Which means it IS limited, one way or the other.
And blaming Samsung for not making enough 1.1 parts is silly as well. These are NOT hot dogs! You can't just set up a line that makes them and then drop them in the package and ship them to your customers! The 1.1ns parts are going to be a VERY small yield out of all their memory chips produced. Only a very small number of these things will pass all the sort and reliability tests at that speed. Most are going to be slower. Some, a lot slower (and end up in the trash at the end of the day). There are things they can do to increase the yeild of high performance parts (things like ... Uh. Sorry. Trade secrets.), but these steps always increase the cost, increase the time it takes to make the parts overall and often has negative impacts on yields. You tweak parameters during manufacturing to increase speed and it tends to push a lot of parts over the edge. Instead of being fast, they simply don't work.
As process improvements are made, the availability of these 1.1ns parts WILL increase. The price WILL come down. And then someone will start using .9ns parts instead for their top of the line card... And we start all over with this debate at the .9ns level.