I'm looking to purchase an investment property in Allentown PA.

Recently purchased a new property with an upstairs attic studio.

NOI divided by purchase price gives you cap rate. 

In Cleveland you could also purchase a property in an area that is improving or on the border of one.

Cleveland and Dayton can be great markets for high cash flow and low purchase prices, but you need to be careful when navigating the neighborhoods so you're not buying in a D/F class area where no property managers will manage and where you'll never see any positive cash flow.

I recently purchased a triplex in Pittsburgh and have had success with it so far.

I plan to purchase a primary residence, multi-family home (2-5 units, 'house-hack'). 

In light of that did the developers wind up getting a pretty decent deal out of this after they took a big risk on a property with crazy restrictive zoning and no clear path forward prior to purchase?

One year after I used that property to pull a HELOC and this year used that money to purchase an off market 4 family property in Clinton for well under market value, which I just recently finished all of the repairs and upgrades on.

Assuming you purchased in your IRA for cash as most do, then there's nothing to deduct or depreciate because the income is non-taxable inside the IRA already.