[1996 328ti]

I don't think it's unreasonable to pay someone to do it as long as they've done it before.
Prices vary from area to area.
Please, it's BRAKES, not breaks.

You should consider a different transmission and diff. Especially a diff.
Only thing to the brakes would be to use vented rotors. You don't need anything special.
Why a new tune for the ECU?

Although you probably could have found a swapped out ti at that price or just a little more.
Personally If I had a swap again, it would be a S52.
But that depends what you want to do. An M52 is more than adequate in terms of torque/hp for the street.

g/l