The "Newman" dial Daytonas are indeed quite rare and the craze is certainly due to Mr. Newman himself. This gentleman has a gold mine in his possession!
Manual wind Daytonas were not a popular watch back in the day due to the engineering put into the screw down pusher crown Daytonas. A manual wind chronograph with screw down pushers and crown? Hardly practical. I guess it's unpopularity was directly related to that design especially that most sports models of the brand were automatic. The "Oyster Perpetual" branding was and still is tremendously popular. I wonder is you removed Paul Newman from the equation, if these watches would generate the same interest?
Due to the immense popularity of the Submariner! The early Sea-Dwellers were also subject to being somewhat unpopular back then as they were, for the common man, basically expensive and over engineered Submariners designed for very the very few who happened to be professional saturation divers.
Yesterday's unpopularity resulted in collector appeal and big $$$. Today, run of the mill references like the later 1675s, 5513, 1680 and now the matte dial transitionals have followed suit over the last 10 years. Although I wonder about the collector appeal of these models (yes, made in the millions) they certainly are marvellous and appealing watches but they have unfortunately become objects used for speculation in my view and this due to their connection with the more desirable models and references.