that sort of thing is collectible, but would not bring a high premium. It's not that they aren't rare, it's that only a few very specialized collectors would want such a thing.
Another example: The Leicaflex SL2 was issued in a special "collector" edition for the 50th anniversary of Leica in 1976, with 1,750 special bodies produced, each with a "50 Jahre" logo and, as an added incentive, a special serial number on the back for each letter of "LEICA" -- so they made 350 of the L, 350 of the E, 350 of the I, and so forth.
So, own an "L" 50 Jahre camera, you have a pretty dang rare beast, right? One of only 350 in the series in the entire world???? Or at least one of only 1,750 in the world???
Not really. I paid $600 for one in EXC-plus from KEH, a bit of a premium, but it more reflected the camera's condition than its collectibility. If there are more than one or two folks out there trying to collect all five, they have them now and nobody else is interested.
Great camera, by the way. I suspect someone bought it to collect, set it on the shelf and left it until KEH moved it on. I use it, as a great camera should be used.