I would say if you have cash available, open the HELOC so you can dip into it as a cushion, but use the cash for the acquisition so you're not 100% leveraged.The only cons are 1) obviously that you're going to pay interest on the money, and 2) the bank will count the interest on the HELOC limit against your DTI when you're looking to get a loan, even if you don't have it drawn. 

From the top of my head I have heard of real acquisitions and propelio.

You plan on using the BRRRR strategy so knowing what the finance terms will be during acquisition and refinance phases are important when analyzing properties.  

It it a ready source of cash to help in acquisition and rehab phases of BRRRR.  

Assuming you agree a market downturn is around the corner, regardless if your next opportunity hit all your criteria, are you planning to be in acquisition mode going into 2017?

One way to look at is that the IRS knows we need those accounts, and that's why we get the depreciation deduction.In terms of cash flow per unit, I only do small multi families, so I can't speak for large apartment buildings, but depending on acquisition costs, anything less than $400 per unit per month in cashflow (after maintenance, vacancy, and CapEX) wouldn't really make sense for me in my market. 

So I really can't speak to that... although with a new acquisition I would recommend "scoping" the main drain by running a camera to inspect it.  

What @Jessica Zolotorofe says about acquisition makes sense in that case. 

I came across 22 acres of land with 4 houses on the land. Seller wants to sell it all. How do I calculate the value of the land?

As a best-case scenario on a $105,000 acquisition (actually more bc there will be closing costs, too), that's still not a good investment.