How to convince an owner to sell or sublease the property to me?

[Oleg Serdyuk]

We bought a condo almost 2 years ago. The unit right below us has been empty since then. 

From looking at the window I can tell that it needs some renovations. 

I know that the unit was bought in 1999 for basically nothing, and now it worth around $300 K. It can be rented for around $1,500.

I also know that the owner is 70 years old guy, who tried to rent it out a long time ago, but it didn't go well because he found wrong tenants. 

I guess since then he is afraid to rent it out again, so the place just stays empty. 

To make it cash-flow investment I'd have to buy it for less than $200K. And I don't think the seller would go that low, knowing the real market value. 

What other win-win deals could I possibly offer to the seller? And how can I approach him?

Maybe I could sub rent it from him? Sign long term rent  for... let's say $1,200 and rent it out for $1,500 ? But what about renovation costs?

Are there any other tricks I am not aware of?

Has anyone came across a deal like that?

Thank you