What to pay for existing, cash-flowing properties?

[John Timmerman]

I'm in Syracuse, NY and have a portfolio of properties I'd like to buy. Market value for all 3 properties (1 single, 1 duplex, and a 5-unit) is about $400k; net cash flow is about $60k a year, and seller is asking $825k (which is very high).

What is fair and typical to pay for an existing investment property with tenants already cash flowing?