The car is almost stalling when you are slowing down I restart the engine and it starts again straightaway first time The car looses all power for a couple of minutes if that.
The garage thinks it could be the crankshaft. What is this and how expensive is it to repair?
Panicking for sure as I am disabled and rely on a car to get me around.
Welcome to the site @sarahDerbyshire, hopefully we can give you some good information. The crankshaft of an engine is what converts the up and down motion of the pistons into a rotation which can be transferred to the wheels, replacing a crankshaft is a big job as the entire engine must be removed from the car and stripped down to get to it, which is very labor intensive, it can often be cheaper to buy a used engine which is working and fitting that instead.
However, from your description of the problem the crankshaft is not the likely culprit. There are many other problems I would suspect like vacuum leaks, fuel supply issues, and ignition issues all of which would be much cheaper to fix. It's possible that the mechanics you have taken it to have better information than I do after seeing the car, however if I were you I would take it to a different garage for a second opinion.
I agree with GdD... Sarah... Take your car to another garage. Even a badly failing crank may give you bad oil pressure or cause a knocking sound etc, however its EXTREMELY unlikely to be the cause of a stalling problem.
The issue your having sounds far more likely to be a general tuning or fuel supply related issue.
