If your can rent your primary house out and it can cover your mortgage, you can count that rental income into your income and you’ll be able to get another loan and purchase another house in market like Atlanta where good houses aren’t that expensive yet.

@Greg GanfiInspector estimated 3-4K each for both furnaces if we count 8k for 2 furnaces and 10k for 2 AC, you’re probably correct 18k does sound high.

They are counting on you giving up and then they do not have to finish.

They will usually count the income from the other three units  towards your personal income which leads to qualify .

It's currently fine where it's at and also, transferring it to my name defeats the purpose of a 'sub-to', doesn't it?

I’m not counting on the cash flow for any of my bills, I just want to keep investing.

I'm also confused on the "brick foundation" concept as mobile homes (even those surrendered as real property) are still installed like mobile homes on concrete blocks and not stacks of bricks.To make this deal work you need to look at the total real property income (in this case the four homes as rentals) and not put any additional value in the potential of the four additional homes as I'm sure the city will probably not let you add them unless they are in the original lot count for the park (as evidenced by the Certificate of Zoning).

Intent counts for a lot here, seems to me the first purchase is fine given your circumstances changes unexpectedly.

Which really lowers you Cash-on-cash (COC) returns, which defeats the purpose unless you are looking for an appreciation play, which is a little risky at this part of the cycle. 

I personally have not seen rates higher than about 14% (not counting servicing fees).