If you do, then you need to come to terms on rent decrease compensation. 

Is there anyway to increase rents/ decrease cost? 

You could reward good tenants to long term 9-2 year leases and decrease their overall monthly rent by signing longer contracts.

It's a close call, but the decrease in your mortgage over 2 years should make it worth. 

In order to decrease the chances of getting into a bad HOA community.

“Never in history have there been more eyes on fewer homes than today.”The housing market has seen a 7 percent decrease in days on the market from last year to 63 days, and total listings decreased 8 percent year-over-year to 1.29 million.

But, on the flip side, with every payment to your first position mortgage you are decreasing the event of that happening as long as you equity add from your first position mortgage grows faster than the market drop.  

@Bill Brandt what are your thoughts on your holdings if not only prices drop but then in turn rental rates drop again as well and your cash flow decreases as a result?

More than likely you're decreasing your IRR as you're putting more money into the deal.

@Peter Morrissey I am not sure how to calculate this, however can't you simply sign up for the STAR program if/when you purchase, so your taxes will also be at the decreased rate?