I agree. You should pay attention to Mortgage Notes in different Zips and talk to a lot of landlords. You can protect yourself but strive to NEVER PAY RETAIL. you can always get value if you ask many questions, like this one, TALK TO LANDLORDS, Prop Mgmt Companies, i.e. serial property buyers.
Oh yeah, BiggerPockets has a great community. I have a regular (borderline guest) account and there is a wealth of info, with constant input (it's popular, lot of users)