He is already naming a price he'd like, knowing what a similar house to his sold for.

He has sold several of his other properties already and has 2 more, including this one.

Mario and Sebastian, I know the Asbury Park area well, having bought and sold in the City by the Sea for nearly 15 years now.

My strategy is to househack a MFR and am looking at a duplex but the seller requires the property to be sold together with the next door duplex.

Personally I have sold homes to people I have met and liked, however it would not sway me one way or another, assuming I had multiple offers.

What I did for our last two purchases that consisted of 4 duplexs and 1 fourplex in two different deals was send a copy from the BP Rental Calculator (Lender said he was VERY impressed) along with a personal 'bio' on both myself and two partners.

Send invoices and copies of bills paid to escrow. 

I created a warranty deed along with a promissory note on a low income property in High Point and sold it to a buyer.

I sold 11 houses my first year and 30 my second.

I would suggest you get some solid sold comps from a realtor and try to have them run in a 1/4 mile radius of the property.