Well paulo2, hard to say exactly without viewing,also depends if you want all wires buried in the walls and sparky to do making good,also depends how much furniture has to be moved and wether fitted carpets everywhere but you should allow for an average job, at least �2,000.00 can you give any more info, cos obviously where you live comes into it as well, My mate for instance in London charges over �200 per day labour, I am on just over �100.in Wales
We had ours done about 3 years ago and it cost about �2000. It was a lot of disruption as all the stuff in the loft had to be moved so they could bring the wires down into the bedrooms etc and then each upstairs room had to be emptied in turn so that the wires could come down to the ground floor. I'm glad we had it done though as we even had some of those old twisted cords on some of the light fittings. We also had the fuse box moved (it was directly underneath the bath - not a good idea!) and then paid extra for the meter to be moved outside so that nobody needs to come into the house to read it.
�2000 is an average price here in Leicester for a 3 bed semi, whatever you do make sure that the person carrying out the electrical work is either NICEIC or Part P qualified as you need that qualification to carry outwork in a domestic dwelling.
I am a sparky and have been for the last 20 years and I don't have the Part P qualification as I don't do any more domestic work, 99% of the time the customer wont pay the extra charges for the Part P certification work you have to do and any extra work involved to bring the property up to scratch, i.e. extra earth bonding...