determining market rent not market asking price

[Albert Gallucci]

I see investment properties that flippers are trying to sell and also have listed for rent. They are not rented and they are not sold. My broker tells me you can get this much rent for this and I dont know how to find varification. When she says that she is basing it on what people are asking. The cunnundrum is maybe they are asking too much and thats why its not rented. Is there any place that list what units actually rented for , not just the landlords pipe dream of what he thinks he can get?