it isnt a hard task by any means ...but if your insistent on paying someone..youll be looking at about 75 bucks..(assuming receptacle is there ).i suggest you buy yourself a case of beer instead and do it yourself...
make sure you put a 2x10 or 2x8 on center of the door 4 feet long( to distribute the pull weight ) nailed to the studs/header in the wall
good luck and give it a go ...it isnt hard