Therefore, I have been trying to study up on techniques used to make good offers and over come objections. 

there are several posts on here about capital calls. without more information it is tough to respond but typically a capital call is because the offering is having issues with cash flow - whether it is because a loan is becoming due or some other reason - that is the primary reason - needing an influx of cash. can you provide more details?

Looking to invest with Praxis, but wanting to compare their current offering with a couple more. 

Unfortunately many landlords take the first group they find in these situations and come from the ideology that all college students are slobs so no sense offering anything nice. 

Two days later our offer to purchase the property + adjacent empty lot was accepted.

These properties also offer you the opportunity to perform cost segregations which help with those current taxes. 

Not having a payment gives you patience to select good tenants and opportunity during the tough times when others are freaking out from vacancy and racing to offer better incentives to put a body in their place.

But you're going to have to offer something in return.  

It offers unique advantages like equity building, tax benefits (e.g., deductions and depreciation), and an inflation hedge, as rental income and property values often rise with inflation.

If everyone uses your tool, and everyone gets the same answer and places the same offer, then no one has any competitive advantage.