Expect to pay around 3 - 3.5k for the full rewire, all chases etc replastered as well...and depending if the property will be empty at the time of the rewire. Sometimes at the electricians discretion, you can pay more if the electrician and his staff has to spend extra time moving furniture etc around every day. As for taking the ceilings down, there may be a reason for this...for example, no access due to tiled or wooden floors that can get damaged. Sometimes this is the only way. On the other hand, it is usual to run the cables for each floor through the floorboards. Perhaps the electrician that gave you the quote is trying to cut his cable costs down.
ADW Domestic Electrical