I got mine from uberclock. Though I know they make china knockoffs for wayy less. (I'd like to try one eventually)
Also, word on the street is they have a smoothie 2 board supposedly coming out sometime (valve time).
Found out too late, but I like mine just as well (ehm, I needed the delta auto level grid routine that marlin/ramps just can't handle). The config is a quite different from marlin but it's a step in the right direction for 3d printing imho.