I'm in a market where actual billionaires buy multifamily properties as 3-caps as soon as they come up for sale (which they rarely do).

And dump out of these top concentrated US stocks into some small-cap growth ones, they are just trying to time this.

Do you mean PITI plus vacancy, CAP Ex, etc.?

We currently operate the portfolio at an 8.5% cap and have moderate cash flow. 

Then you get into a four family, and if you are not going to occupy, your loan will likely be capped at 75% LTV.  

An average gastroenterologist earns 400,000 a year and that likely remains a cap as one can only shove so many camera per appointment and have only so many appointments per day/per 52 weeks. 

Here are some tips to help you find and distinguish cash-flowing properties beyond the 1% rule:To evaluate a property's income potential, consider alternative metrics like the 1% rule, cap rate, cash-on-cash return, and gross rent multiplier (GRM).

Even though you are buying new, I would still account for vacancy, maintenance, and cap-ex when calculating cash-flow.

Well you cant BRRRR at 7% interest rate in a market that pays 3% Cap Rate on rentals.  

I was wiped out as second lien holder which got me to thinking about legitimetly becoming a private lender.My question is if I already make 7.5% off a few of my 250k condos, then how does private lenders (not hard money lenders) make money off charging 7-8% returns when they can just purchase condos in cash for the same CAP rate?