I would think you should approach some local banks and see how they will handle your situation.

Real estate investment can be incredibly rewarding, between the cashflow, appreciation, and tax benefits, it truly is the greatest wealth creation tool. 

The market has been incredibly robust the last few years and I don't see that changing anytime soon especially as mortgage rates continue to decrease.

I’m especially interested in the "why" behind your approach.

Cost approach A straightforward method that adds the cost of the land to the cost of building construction.

The biggest hurdle I see with arbitrage is developing a pitch to use when approaching landlords, which you can probably do with a little research on BP and ChatGPT.

(For example, IF I was able to purchase the first home (multi-family) outright, paid-in-full, then use a HELOC to pay for the down payment and closing costs for the second home, would that be a smarter approach?)

I know I could have a family member co-sign a mortgage with me but not sure the best way to approach that conversation and what incentives I’d be able to offer to make it worth while for them other then their “familial duties” haha. 

Residential property rental: Could this be a scalable and profitable approach, or is it too risky?

Quote from @Fernando Martin-Gullans: Hey y’all, I’m a retail investor with 2 SFH rentals worth a combined ~$650k looking to utilize some of my stored equity to buy more out-of-state properties, but I’m not quite sure how best to proceed given that my interest rates are incredibly low (leaning me away from refinancing) and neither property is owner-occupied (which I believe prevents me from using a HELOC).