How to spot a good deal for buy and hold in Baltimore

[Susan Bmore]

I have a question for my buy and hold folks. 

I see all the time landlords trying to sell their properties and stating that the property will generate x dollars in cash flow.

I am curious because if the property is generating cash flow why would one want to sell at a discount especially when the ARV is high.

I am starting out myself and want to know how do you spot a good deal vs someone who is looking to get out of a bad situation.