The property must be your primary residenceSingle Family, condo, or 2-4 Unit3% Minimum Down PaymentBelow is a comparison of Conventional vs FHA.Both are assuming no point loans.Conventional LoanLoan Amount $450,000Rate 4.5%Term 30 Year FixedPayment $2,280.08 – Principal & InterestPMI $172.50Total Payment $2,452.58FHA LoanLoan Amount $457,875Rate 4.125%Term 30 Year FixedPayment $2,219.09 – Principal & InterestPMI $316.08Total Payment $2,535.17 You may want to look into this loan product.

With the amount he has in his account and no mortgage he should be able to handle vacancies and repairs, this is a valid point, reserves are essential. 

I also have the tiniest amount of experience in real estate investing, I flipped a townhouse in my 20's, and help my family run a few airbnb's and am a new real estate agent.

I calculated the amount of interest payments i'd pay the lender for the first year alone and it amounts to about 22k.

Some banks allocate how much they can loan for different amounts of money.

Tell him you’ll do 15k down and X amount each month with interest over X amount of years .

Would you borrow big amount of money to someone who doesn’t have any savings ???

Hey-- I have spent a lot of time in Miami growing up and have also done a fair of amount of scouting for AirBNBs in the area.I feel Miami can be a good market, but you'll face a couple of issues:1) HOAs will usually not allow this in any building2) To do it legally, at least on the beach, you will likely need to buy in a Condo Hotel. 

If they do the closing they will charge some set amount.

It exists because it is basically the minimum amount that can be used to transfer title.