Investigating the Apartment Building Realm

[Jack Calhoun]

Hello, my wife and I are looking into the 40+ unit apartment building arena. We have looked into a couple of handfuls of buildings and are having a harder time deciding if it is a good deal or not (we have only bought 4-plexes up to this point). Are there any of those "rules of thumb" to help give the big yay or nay? 

Thank you BP World