@wingleaf no need for law firms, but they will charge you 100-150 per page, ordinary notaries will cost you 50 per page at most, just tell them what needs to be in there:
The following information is required on each page of your certified copy:
The words 'Certified True Copy of the Original'
The <b>signature</b> of the certifying person
The <b>name</b> of the certifying person
<b>Registration number or title of the certifying person</b> (e.g.: Police Officer, Doctor)
Certification details must be legible on the copy and the certification should be <b>dated</b>
*in my case was able to find one at Pasay city hall, I did it in bulk so I was charged 30pesos per page & that was accepted by ACS.