Yes. It's the only way to get that level of detail that I'm aware of. If there are other sources of data in very interested.
Future options, to get away of self-reporting, could include scraping deed recording (which don't include prices, but could give Disney ROFR percentages; assuming Disney files the same way) and trying to pair them with resale listings, which usually only show list price, not final price. That's a lot more work for worse results at this point IMO. This data could be useful separately, somehow, though.
Another option could be to partner with resale companies to get anonymous data. I haven't reached out to anyone for this.