@Jeremy Mattson, I have missed and continue to miss good buying opportunities because of a lack of funds. 

If you are happy with the cashflow once you rent out the fourth unit, I vote HELOC and leverage for a few reasons:-You don't pay taxes on the equity you use from a HELOC-Closing costs are free-You get to keep the property and continue to appreciate.

Are there any we are still doing it this way but don't see the trend continuing much longer?  

So my tenant said "OK, if that's the way you want to play it, you're illegally running a rooming house, I know others do it in the neighborhood, put they respect their neighbors.

I would rather surprise to the upside than count on continued high rent growth. 

I would like to continue leasing.What are your thoughts?

I will continue with my research and try to find the best deal I can.

It's an appreciation play. 

Definitely continue to interact and ask questions here on Bigger Pockets and try and learn as much as you can and take action on the wisdom you gain.

That's going to play a big role when you refinance in a year like you mentioned.