You need to pick your qualifying statements, because you're confusing things.

First you wrote "all things being equal." Then you wrote "then it seems something that had held up better." You can't have it both ways, so which is it? Are the elements in question --- black and white versus color --- "equal," or did one hold up better than the other, in which case they are not equal.

If the former, and the elements both held up well, there isn't much difference in the cost involved in transferring them to video (whether HD or SD). If one held up better than the other, the one that held up better is going to take less work --- and less cost --- to transfer than the element that had deteriorated. That's true regardless of whether the elements are color or black and white.

Which brings us back to your initial erroneous statement that I was responding to:

You made no qualification of good quality elements versus deteriorated elements. It isn't much "easier" to transfer black and white film than it is color film to Blu-ray. You need to adjust the color balance a bit, but that's no big deal.

I wrote "all things being equal" meaning that both were films, as I thought the gist of saying that black/whites are usually in better shape, untreated, would be readably apparent. Sorry if that was confusing.

If it's still not clear, the equality is in reference to comparing color to black and white being on the same medium, that is both film or both video.

I was making a general statement earlier, which you may not had caught onto fully, that my limited experience suggests that non-color holds up better than color, for older films anyway. So in general it would be cheaper to transfer and digitally remaster black and white than color (you do agree that prints is better condition are easier transfers, though I thought you thought the opposite), that is, if you agree that black/whites tend to hold up better than colors. I don't say there's some mystery as to why black/whites hold up better in general, it's just something I've noticed. The rate of murky color pictures and clearer black/whites is pretty noticeable. Unfortunately, since I don't know a video from a film, what I may be seeing a lot of murky colors come from videos, while a lot of the black/whites may be film.

So when did motion pictures start being used heavily on video? Would it had been about the time VCR's were made available to the general public or maybe a decade before?