It is possible to bury the cable but the feckers hate pulling the rope thru the ducting (One crew i had dealings with broke the rope on 4 houses on purpose) lazy shits ,
The pipe has to be layed on pee gravel or sand base , then the esb ducting is rolled out into the trench and a warning tape placed on top , further pee gravel or sand is then placed to cover the ducting , then backfill trench with excavated material or suitable road base material if its under your drive way or paths , as ker said use a hockey stick to bring the wire up the cavity of the wall ,Make sure to place the pull thru rope in the duct or they wont look at it ,
Generally the metre box is placed to front or a gable wall for ease of access when reading the metre for the bill to be calculated ,
As far as i can remember the cost is varied on each job due to the fact that no 2 jobs are the same