Seller Second Mortgage on an 80% LTV First Mortgage

[Micaiah Marquette]

Hey guys! 

I'm new here and I have spent a couple of years studying real estate investing strategies. 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. This strategy is a combo of subject-to/seller carryback. Is this a common method or not? Let me know your thoughts on this!