As the conversation started, I realized that the caller looked at me as someone who could help her, and it put me at ease.

I would suggest looking in the rust belt and mid-west .... you could get 8 SFRs, 6 duplexes, two quadraplexes or one octoplex for the price tag of that 250K(ish) duplex you've been considering.Ironically I had a cold caller today from a turn-key outfit in Columbus.  

However bandit signs are illegal in many areas and can lead to heavy fines.You would screen the callers just like you would those who called from your mailings.

I called my sister to complain about my problem finding a good cold caller.

Before I sold other properties in Cleveland, I spoke to a few of the callers and found that they would offer much lower than I eventually sold it for on the market. 

Be blunt with this with callers, something like "potential renters must have $3600.00 in hand in order to sign a lease ect.

:@Jonathan Bowen Long time listener, first time caller.

The language in the guidelines is specific to trying to sell people a product or service, so I don’t know that it prevents anyone from trying to purchase (unless the caller is a realtor trying to sell the service of listing their property which is specifically mentioned).