Need some advice on this Duplex deals

[Patrick Rowe]

I have an opportunity to purchase 3 Duplexes for $270,000. The owner is liquidating all of his rental properties that he's own for 40 years. I talked to a realtor and asked her to send me the expenses and she said the owner doesn't have any? She stated that the tenants pays all utilities  and cuts the grass. These are the umbers below , let me know what you think will be a good offer. I have a banker that will do a 30 year  loan with a 20% down payment.

Duplex 1   3BR  2BA / 3BR 2BA rent $1400 per month 2600 Sqft

Duplex 2   2BR  1BA /3BR 2BA rent $1350 per month  2400 Sqft

Duplex 3  4BR  2BA /3BR 2BA rent   $1450 per month  2900 Sqft