They're not a limited run, like other products that are marketed as limited. They just can't churn these lenses out at as high a rate as other mass produced lenses because like selar said, they're assembled by hand. I do see them go out of stock from time to time, at least the FA Limiteds; not sure what exactly the reason for that is though. What I can say is that the three Limiteds I have are excellent lenses: top quality, all metal bodies and optical performance that won't disappoint. The build and feel are superb! Looks like you probably already knew that though from having the FA 77. I suppose using "Limited" is a bit of marketing nonsense. It's worked on me though, cuz I feel special having them.