Interesting questions, you present.
I believe that if the general market for collectibles / vintage watches stays strong, then the Blue Monacos (and other Heuer icons) will continue to rise. The good ones are getting scarce; a lot of stuff has cycled through ebay over the past five years; there is a lot of spare money in the world . . . the weak dollar causes some big numbers to show up on ebay, when the auctions are priced in US dollars.
In terms of my new black Moanco, I have chased several of these over the years, but have never bagged one. On the one that I bought, if you can look beyond the roughed up case, and the weird needles, then the dial is actually very good, and it is genuine. My plan is to clean up the case, replace the needles, chrono second hand, pushers and crown, and see how it looks. The most significant improvement will be the least expensive -- with a new crystal, this will look a lot better. For me, you are really buying the dial, and this dial is good -- the rest can be replaced / improved / fixed.
Stay tuned, as the rehab project progresses.
Jeff