Imagine if it cost 1000 to send out 50 letters but half of them responded and half of those wanted an offer and half of those accepted an offer and half of those closed and half of those resold for a net 50k. 

Would going to local real estate meet ups be the best way to find potential investors I could partner with?

You can also assess a dollar amount that you value the cost of these requests to be, and ask for these as a discount from the purchase price or a concession to you for closing costs. 

If you paid $950k and only get $1M after selling costs, don’t bother with the 1031.

Multiple people including myself have tried to caution him of the the true costs but he's been repeatedly dismissive and has made it clear we give him motivation and he wants to prove us all wrong (whatever that means). 

@Yael DoronIf you're working with a $150,000 budget and aiming for high ROI through rental income, consider nearby areas around Phoenix that still offer affordability and growth potential.

It's probably best to have them pay out of pocket for a smaller cost like this.

If you're in Northern MN, there is a very good chance that the cost to build a new duplex exceeds the resale value, which would be an awful idea to build a new one. 

But, these broad market studies are so large, they are almost meaningless, in the real world.Between glut of new supply in many "hot" markets coming online, a continually softening economic outlook, inflation over last couple years making day to day items feel cost prohibitive, many average renters are strapped and seeking lower cost housing.  

The easiest way to find and connect with wholesalers is either bigger pockets or by googling "sell my house fast in (town name)" although that may cost them a click for google ads.