Jennifer finds out that Superman's Mom borrowed $6,750,000 to purchase the DPH. First Republic provided the financing by lending the same dollar amount they would have lent to any Qualified Buyer who had purchased the building for $9.0MM. The interest rate on the loan was 7.25%, Interest only for 10 years. Using just a) the spread between the cost of debt, and the expected BTIRR and b) a Leverage Multiplier, ESTIMATE:

What BTIRR can Superman's Mom Expect on her Equity Investment?

Assuming Jennifer can obtain finanacing at the same LTV (assuming this purchase price represents the value) that the bank would have lent to Qualified Buyers of the DPH and the same interest rate (interest only for 10 years), what BTIRR could Jennifer expect to earn on her equity investment in the WH if she pays $9,000,000?

IF Bruce Wayne agrees to provide 90% financing at 7.00% interest only for 10 years, What Price could Jennifer pay to get the same expected Return on Equity (leveraged) as in b above?

Is there anything about the parameters of the questions a, b & c above which makes the estimation method used to answer these questions less valid than usual?