NGC puts a premium on points for ultra cameo, but are these really more rare than higher graded coins without ultra cameo?

I collect proof Jefferson nickels and have all but one from 1938 to present. To move up the registry list on the late proof Jeffersons from 1965 to present, there are only three options:

1) Get PF70 UC examples. PF70 UC is worth 102+ points, but anything PF69 UC and below are worth basically nothing. I have all PF70 UC from 1990-S on, but anything from the 1970s or 1980s are rare and expensive - much more so than the points they are worth.

2) Buy SP70 for 1994-P and 1997-P. The points for these are skewed way more than they are worth. They are not cheap, but all of the top registry sets have SP70 examples, which can readily be found on auction sites.

3) Get Ultra Cameo SMS nickels from 1965 to 1967. This is the point of my Journal Entry. Almost any Ultra Cameo SMS is worth more points than even the highest graded non-cameo or cameo versions. I have MS-68 coins for 1965 and 1966 and MS-68 Cam for 1967, but I could trade all of them for one MS-66 Ultra Cameo and still be ahead on points.

I guess the bottom line is that the Ultra Cameo SMS and PF70 UC / SP70 are so overweighted in the NGC registry points that it makes it difficult to put together a high ranking set without them. Registry points are very important, yet they don't seem to accurately match the rarity or cost of the actual coins.