Welcome to the group! 

My idea to buy a home is to get an 80% LTV 1st mortgage from a bank, take over that mortgage and give the seller a second mortgage for 50% of the 1st mortgage balance because I need some cash to cover the payments, which the amount of cash would be more than the remaining equity in the home.

Here is their website: https://www.hometeamvr.com/

Is there a demand for housing in the area?

Also, you are not buying at a premium and can allow the property to appreciate if that said area is historically improving. 

As you mentioned often they own the land/house next door. 

That gave me a bit of a taste of what real estate can do if you find the right deal but I had no idea what I was doing at the time.

In 8+ years the answer to us has always been No.

The higher you go in price, the ratios get too hard to make it work without leaving as much money in the deal as you would a standard down payment.

DSCR loans are great options when the borrower has good credit and the deal is really solid.