I came across an awesome opportunity for some rental properties I'll outline to you.Seller has a 7 unit, a 5 unit, and a 4 unit.

You didn't ask but to confirm - yes you can combine sec 121 primary residence exclusion and a 1031 exchange to complete eliminate and defer all tax on gain from the sale - a great strategy. 

You are landing one wholesale deal per week/week and a half give or take, based off your numbers?

I have used seller financing from both a buyers position and a seller's position!

There are many cities like this across America, and as @Matt M. mentioned, those economic factors don't turn on a dime barring major political/economic events.

@Christian Cody Financing costs are specific to the owner/investor and as such are not included in calculating NOI.the mortgage debt is not in that $20K #

This sounds like a good idea and a good way to save money, but like @John Warren pointed out, it is rarely worth it in the long run. 

I’m a Multifamily investor living in MO but have a complex in Ft Smith and a duplex in Fay but looking for more. 

When I started here 5 years ago there were 120-140 properties listed, but in the last year and a half it has dropped to 60-70.

A year and a half ago I was like most in the world.