1st deal - how to make offer on a house that's not for sale?

[Matthew S.]

Could really use some advice.

History My wife and I have owned a duplex for the past 12 years, and have it and our primary residence paid off. We have decided to slowly buy-and-hold more rental properties with cash.

Opportunity The house next door to us is a rental, and the landlord has had it since the 1970s (originally paid $6k!). It's small and not in great shape, but on a "hot" street that has seen a ton of rehabs over the past 3 years. The landlord owns multiple properties across the city. I'm sure he's been contacted by mail by folks offering to buy it. It seems inevitable that someone is going to make him an offer that he'll take, tear down the house, and build something nice on the lot.

I want to make him an offer, hold the property, and continuing renting it for another 5+ years. Then I would tear it down and build a SFH or a nice duplex to either rent out on a lease, or even do a VRBO/AirBnB-type situation (which would be convenient to maintain since it's next door).

Problem I have NO idea how to approach the guy– I think I have a current phone number for him, but as this would be my first deal, I don't know where to start. I don't know how to accurately assess the value, how to make him an offer that's low enough that I'll feel good about it, how to find out how much he's receiving for rent, how to re-approach him if he turns me down the first time. Again, I'm a total n00b. I don't want my fear/inexperience to paralyze me from action though. I have about $50k that I could use to make an offer now, and will have at least $85k total by the end of the year. Zillow Zestimate has it at $77,069. 762 sqft SFH.

Any advice would be appreciated!