Sam is a property investor. He purchased a small commercial building in Sydney for $2,000,000. Sam had to take out a loan from the ANZ Bank to purchase this property and Sam is charged interest on that loan. In order to rent the property, he met William, who is an experienced real estate agent. Sam and William agreed that an upfront lump-sum payment of $8,100 as a management fee is to be paid to William. 

With reference to the relevant legislation and case law, discuss the issue as to the deductibility of the management fee to William and the bank interest charges.