He wanted to know how the initial figure of $75,000 quoted for the review had blown out to a "disturbing" $230,000, or $12,777 a page. The council also paid Crown Solicitor Simon Moore, QC, $20,000 for legal advice.
On Friday, Mr Brown agreed to pay $40,000 towards the $250,000 bill for the report and legal advice.
The council confirmed media reports of the cost in the "interests of open process and public interest", but refused to explain how the EY report increased to $230,000.
The report was supposed to take no longer than four weeks but stretched to seven weeks.
Under scrutiny
$230,000 the cost of an 18-page report into any misuse of council resources by Mr Brown during his two-year affair.
$20,000 was also paid to Crown Solicitor Simon Moore, QC, for legal advice.
$40,000 what Mr Brown has agreed to pay towards the bill.