Unless this is some type of homerun deal, which I assume it isn't if the mortgage is upside down, then why bother?

As noted, if your options are Reg D, private offering vs fully registered public offering, even if you are talking Pink Sheet (OTC) stocks, you have public filing costs, annual audit requirements, and likely more on-going expenses that have to be covered by the property(s) owned by the offering.  

You will find like minded investors, vendors, private money…etc. good luck!

Investment Info:Single-family residence private money loan investment.

I was buying homes for $100k with $25k of my money, and the mortgage was paid off by the tenants.

If I were to approach a seller of a $200k home, and they had a remaining mortgage of $100k, could I get a new bank financed loan for that $100k, and have the seller finance the remaining $100k of equity to me?   

Quote from @Collin Luckett: I have a couple houses I’d like to put under contract as fix and flips and would like to you private money lenders to help fund.

Quote from @Burke Atkerson: With over a decade of real estate investing experience and over 100 flips, I now provide private money & hard money loans.

In fact, a couple of recent studies have shown that working with a broker typically saves about $10,000 on a residential mortgage.

I took a small private loan and bought my first home.