Wouldn't it be more reasonable to assume that a high percentage of the divers that invested the time, effort and money to reach rescue diver level will upgrade to at least the DM level?
As others above have stated here, Rescue to DM is not part of the typical progression... DM is the start of "going pro".
But to answer your question directly: no. In my observations as an instructor, I saw a fair number of people take the Rescue course (and I encouraged my students to do so) but very few of them expressed interest in becoming a DM.
As for the time, effort and money... I think the investment of all of those is greater for just the DM course than for OW, AOW and Rescue combined.