Have you tried the Polsilver blade?
I find the Polsilver basically as sharp and smooth as the kai, but at half the price.
And don't forget the Moscow blades, Rapira and Voskhod! Excellent blades for me in the Rockwell. Sharp, very smooth, and cheap. The Rapira Platinum lux is like 8$/100, almost a steal.
Going to load up a lot of them just in case.