I don't have specifics, as I don't own any rental properties. However, my friends in the business say that they buy rental buildings without any real consideration of resale pricing. They're buying for the long haul, and want good buildings with good tenants and a steady cash flow, with a return that's greater than what a high interest bank account would provide but are not expecting returns in the double digit percentages.
Any increase in the value of the property is a bonus, but not a main consideration because they're not speculating on real estate price swings.
BTW, most of the time they are paying for this in cash. They usually already have the money, so mortgages are not a consideration. And if they don't have the cash, they go in with a group of investors, each with 6-digit $ to invest in cash (often from wholly owned but separate companies). The problem here with having a significant mortgage is that it will eat away at the return, and could put you into negative return territory. In that context what you're really counting on is future returns, and future resale value, but this is not how these people work. Or at least that's not how my friends and their business partners work.