Just my 2 cents...
I used spb ms 2 & 3 on winmo for a while, then always back to touchflo3d. For me it was more efficient. But when I tried android on my winmo, I was sold. The homescreen and widgets were just my style. Now with my droid I run GDE. It keeps the look of android but adds some functionality.
IMO, spb sold well on winmo because winmo's touch interface was only touchable with a stylus. If they come out at a $30 price, I think they should just call it spb 4, b/c it will fail. But if it is as good as it was on winmo, maybe 10-15 would be fair.
In the end, this is still why I am loving android, lots of options to customize and make it your own. And Spb made some other great programs for winmo. I would like to see what else they can bring to android.