Best way to approach a specific owner

[Ari Bachrach]

There's a house near me that I'd love to buy and flip. It's a great neighborhood (I live there - of course I say that). To give an idea of the neighborhood, houses like this one usually go for 500-600K. This particular house has been empty for several years. The owners moved and still live in the area but never bothered to sell the house, never rented it, and it's sitting empty. I have a GC and we'd love to flip it. My impression is that they have the kind of money where they can afford to do things like that, plus the mortgage is all paid off so their expenses are minimal. 

I need some ideas. What's the best way to approach this? What can I offer them? Most people need a house to be sold quickly and are willing to compromise on price. In this case they obviously don't care about the timeframe, and I feel like they probably won't be motivated by money. How would you approach this?