The prices should be delayed two months. The rate at which pricing information propagates dictates how much of the rental pricing mass (number of owners * average units owned) gets thrown around how quickly. I don't have a number, but something like 2 months. Treat this data as if it was a vile of Devil's venom [1]. If they setup back channel information sharing networks, or collusion networks of any kind. <bad thing happens, not just a fee>
Second, the historical database should be deleted. And if they can't survive that, so be it. Keeping the spoils of crime should be the crime. Justice still isn't finished.