I'm not sure how to reliably evaluate these as rentals.

Paying down the loan is economically equivalent to investing at 6%, making it (obviously) the inferior choice in this particular fact set.Without a doubt, you MUST also evaluate other factors.

Something does not seem add up.Since you are considering renting I would use the 50% rule and 2% rule to help evaluate those properties.

So, when I evaluated the building, I knew what the rents should be.

To help you crunch the numbers on properties you're evaluating, maybe keep track of rentals you own, etc

After all I'm comparing rents in Houston in 1982 during an oil boom to rents in Denver in 2009 during a recession.I don't agree with the contention "no other investment is evaluated after inflation".

Than, how do you evaluate it?

You may need some seed money to do your initial evaluation and planning.

If the property has been rehabbed already, unless there is a tenant in who committed for the rental amount, any claim is a ball park only but at least that ball park (Due diligence required) can give you an estimate of what the property worth based on 1%, 2% or whatever formula you choose to evaluate that property.

More importantly it will allow you to evaluate potential deals quickly and more accurately.