thank you for posting this camera into the catalog, I've never seen such version before. I wonder how many were made, any information can be found on it elsewhere? I'll search the internet for some info as well. Quite intriguing.
I believe that this version was only produced at the end of 2003 and during 2004. I don't think that the production quantities were large, but they are now freely available due to the fact that I would imagine that they are not particularly popular. (Why buy a camera that is designed to have interchangable film magazines, without this particular advantage?) I suppose it is possible that the Arsenal factory decided to use up old stock in this way in order to clear the shelves. Originally they sold for only a quarter of the price of a Kiev-88CM body + film magazine.
This model Kiev is similar to the Bronica ETR-C of the late 70's. While Bronica manufactured their primary model, the ETR with interchangeable magazines, they also made the ETR-C with added inserts you could place in the fixed "magazine holder".