Quick Analysis of Mutliple Duplexes?

[Jeff Lever]

What would you pay for 3 Duplexes (6 units) in what appears to be pretty good shape - fully rented w/ each unit bringing in $625 on average ($3750/mo)?

Property is also an hour away, which means that more than likely we'll have to use a property management firm to handle tenant issues and maintenance costs. I'm not sure what landscaping costs would be, but it's a very open/flat space that's about 1.5 acres of 99% grass. 

Brick duplexes all look to be in good condition w/ no deferred maintenance, on septic systems, tenants pay all utilities. 

Just ballparking it right now to see whether the asking price of $500k is fair or overpriced?