R.O.
I forgot to ask,why specifically open houses? The vast majority do not identify houses they think are good deals or that they buy, via open houses.
I get the impression that you are not seeing some of the good stuff that happens here(on the blog), both towards coaching people who are buying or selling, including helping people decide not to do either.
I like your idea or some version of it. i just want to point out that there is already plenty of good information sharing here, once an area merits it or when someone specifically brings it up. Take the active Murrieta thread for instance and threads by Raptorduck and others who admit they are shopping.