Sure, but they believe the market isn't at the top. Opportunity cost could continue to increase until they cash out. That is, maybe they could sell for $10 mil

Sure, but they believe the market isn't at the top. Opportunity cost could continue to increase until they cash out. That is, maybe they could sell for $10 million now vs making $200k per year on parking, but if they hold on for another 5 years, the offers could rise to $15 million.