If its a couple of cables do it yourself. We do most things in house, saves a fortune.
The only time we would get a contractor in would be for a full room.
A box of CAT 5 is ?50 ish for over 300m, a punch tool is ?10, crimper is ?15, rj45 heads are ?12 for 100 and some push rods are ?10-?15. The only thing you need after that is time and a ladder.