Getting BT to connect up the phone line?

JustAnotherSaver

So we're looking at being good to move in about January time. One of the things we'll need sorting is the phone line since we don't currently have one (it was disconnected).

The wall where the main socket is/was has had some work done on it & some of the wires have snapped.

This wall due to poor workmanship is going to require more work at some point. In fact, the entire living room needs sorting, but that's one for some time next year or the year after as it's going to cost quite an amount.

1. How much do they roughly charge for this?
2. How long do they take to do it (both waiting time on them coming out & the job itself while they're there)?
3. Would relocation of the master socket cost more? Would you advise against this? At the moment it's in the living room, but like i say, the wall the wires come through is probably going to have to be stripped & started again. I also don't fancy the modem/router being left on show in the front window.
4. What if, with the broken wires, they need to re-wire? Does this mean drilling in to the living room (or whichever room if a relocation) from the outside or could they just feed it off of existing wires ok?