., up to $750k mortgage)- savings on paying rent (i.e., the rent you are currently paying)If not, drop in your thoughts on which value drivers need to be included and I can pull a quick one together. 

We built an ADU, 2 bedrooms + loft for $300k.The downstairs mother in law unit makes about $17k a year (gross).We live in the main house.The new ADU makes about $65k a year (NOI) as a STR.The mortgage is a $500k 30 years fix mortgage at 3% interest rates$2,500/mo.Cash + Mortgage: $500k + $530k= $1,030,000ppraised for $1,400,000Cashflow: $5,000/month 10% cash on cash + live for free.: $400k for $530k invested, so 75% return.

In terms of finding funding, BiggerPockets just released a video yesterday talking about this called NEW LOW Down Payment Mortgages Are Here (Put Just 1% DOWN) which might help.

Buying a single family property with a 7.5% mortgage and holding it for 5 years will show right at an 10.9% rate of return.  

Living in the home has helped us save on our monthly mortgage payemtns and we've been able to buy Airbnbs because of it! 

With rent equal to mortgage payment, this house will be paid off in 12 years with higher appreciation and possible cash flow after 2-3 years from now. 

I cannot show that I live there, it seems a 2nd mortgage to tap the equity is my best option.

-Offset personal mortgage expenses with income from tenants rent.

Also I'm planning on using a HELOC for DP and rehab so I was hoping to just get a mortgage rather than a specialized loan based on ARV.

This is called getting a loan, and you'll need to pay them back over time.Sometimes, there are special helpers called banks or mortgage companies that can lend you the money to buy a home, and you can pay them back a little bit each month.