US estimate circa 2023 is US $2,000,000 to $6,000,000 per mile. This is for main lines only, not secondary connections to residences or businesses.
Don't know anything about easements in Jamaica, but granting an underground easement on private property for public utilities in the US is time consuming and costly.
Most US Electric utilities are pole mounted unless local zoning requires utilities to be underground. My subdivision west of Boston required utilities to be underground when it was built in the 1980's.
One suggestion would be to use concrete poles instead of wood, but again, the cost is greater.
Hope you are doing okay?
VVHT aka Happy
Years ago, after Ivan, concrete poles were being seen replacing the wooden poles. It was common to see an old wood pole next to a full in use concrete pole.
Then, all of a sudden it stopped. No explanation was given at the time.