2,800 is still expensive. But of course that's because you're contracting out the whole job including making good and this would be considered as specialist job.
It's essentially a DIY job really and you can get the electrode and wire over the net. One good option to check, is to pump a silicone creme into the walls. This would be as effective as the wire and is also a DIY job. Of the two, my research on the topic would lean me to the silicone creme (Dryzone is a brand name with BBA approval and can be bought in ireland).
Doing it DIY should see you spend no more than 1100 euros.
However before you settle on either of the above, check the ground levels out side the house and reduce it to 6 inches below the inside floor level. Look for tress that are near the house as roots from these will be drawing water up to the foundations. These may need to be removed. Also you could put in a french drain around the outside of the house to drain away any moisture from the foundations. Doing these would go a long way to solving your damp problem without too much cost, especially if you do the work yourself.