This is a question to which the full answer may not yet be completely understood!
First: My observation has been that the TV lens sells for less than the RF-coupled lens. Maybe the trend recently has been different, but if so, that's just an eBay peculiarity.
Here's my understanding of the situation, which I admit is TENTATIVE:
1) Originally there was an RF-coupled 50/0.95 lens, designed for and introduced with the Canon 7 camera (which appeared in 1961.) Distinguishing features of this lens include a special external breech mount for attaching to the camera, a ground-off flat area on top of the rear elements to make clearance for the rangefinder coupling tab, and the tab itself (a flat brass piece that extends rearward across the flat area vacated by the ground-off lens element.)
2) There also was an official TV version of the lens; I am told (don't know firsthand) that it was engraved "Canon TV Lens" on the front ring, had NO flat spot ground into the rear element, and no coupling tab. I believe this version also had the external breech mount and shipped with an adapter that converted this mount to the semi-standard TV-camera "C" mount (semi-standard because the thread was standardized, but not the mounting depth, which had to be adjusted on the individual camera.)
3) This is more speculative, but I also have heard that Canon's then-US importer, Bell & Howell, disposed of some of its RF-lens inventory by making its own "TV" version. This consisted of the regular RF-coupled lens, complete with flat-spotted rear element and coupling tab, but sold with a breech-to-C-mount adapter and distinguished by a small black-and-silver rectangular "TV" sticker affixed to the top surface of the lens barrel, forward of the aperture ring. The 50/0.95 I own has this sticker.
Since the breech-to-C adapter could be moved easily from lens to lens, and since the TV sticker could be applied easily to a photo lens, AND since it's pretty easy to separate the front lens group from the rear group (remove a single setscrew and unscrew) it would be easy to create any number of odd mix-and-match hybrids: such as repairing an RF-coupled lens with a damaged front element by removing the front group and substituting one from a TV-marked lens, or vice-versa. This makes the whole question of exactly what's a photo lens and what's a TV lens somewhat confusing!
I've read an item description from one Internet seller stating that the TV version of the lens is later, has more advanced coatings and better glass, etc. -- but I strongly believe this is just eBay hype.
It used to be that the RF-coupled lens was somewhat more desirable than the TV lens because if you wanted to convert it to M mount, it was easier if you started with the RF-coupled version. Now that there are instructions running around the Internet about how to convert a TV-mount version by adding your own coupling cam (in some cases by sticking a blob of epoxy on the rear element!?!?!) it could be that do-it-yourselfers figure either version is equally good.
I'd have to say that I'd be extremely skeptical of homebrew TV-lens-to-M conversions, especially those involving sticking adhesives to the rear element. The focusing accuracy demands of this lens are very high, as you'd expect with an f/0.95 maximum aperture, and I doubt that anyone other than an expert technician could bung up a coupling cam that would be consistently accurate.
Obviously there's still a lot of tracking down to do on the history of these lenses...
