Approaching -Plex Property Owners

[Todd G.]

I've located several -plex properties in town - none of which are for sale.

The owners live in-town (not in the actual properties, though), and I'm considering approaching them to see if they want to sell. 

In the past, I've done yellow letters, but I'm not inclined to use that approach with these folks. If they don't want to sell, no problem. However, I'd like to be able to build a relationship (of sorts) with them, and be the person they call when they ARE ready to sell.

Any thoughts on a novel approach to these folks?