Rough estimate/average ORM cost/time frame

I know every ORM case is different. But for an ORM case where you have to derank a .gov site among a few others, I'm trying to get a very rough estimate / idea of how long it would take and what it would cost?

Again, I know there are thousands of variables that effect these but just looking for a ballpark idea.

Thanks

Had a client with a uncommon first name listed on a couple commercial (.com/.co.uk) websites and a .gov website, it took around 40 hours (billed) work to bump these listings down to the second page.

40 hours @ £35 per hour, £1400 + billed £100p/m as maintenance for min 12 months.