What does it actually cost to run a lead platform on top of a full time W2 job

I manage leasing and turnovers across about 900 units so my weeks are not predictable. I have been sitting on this idea of scraping notice-to-vacate filings in two or three counties and selling the data to investors, but every time I try to scope the build I get stuck on the ongoing piece. Not the first month, the ongoing month. Somebody has to watch the scraper, QA the records, handle a buyer who says a lead was bad. I do not have a VA. I do not have a co-founder. I have maybe 6 to 8 hours a week that I can actually protect. Has anyone here built something like this while still working a real job, and what broke first?