As a former software developer turned Realtor, I concur with your findings... FWIW: even as an agent, trying to get MLS data into formats that are easy to dig into for interesting patterns is not easy. You might have better luck talking to your local title company or seeing if you can scrape data off your county tax assessor site.

In my market, I can absolutely tell you where those diamonds are, because I'm in the market daily. That might not be the answer you want, but finding a skilled Realtor you like / trust who can get you into opportunities is the fastest path.