ABS Fault, have fault code readout....

[nemeth782]

Hi, I posted a while back about an intermittent fault with my ABS (car is a W(2000) Bora 2.8 V6 4mo, so full ESP etc)

I have now had the fault codes read, and would be interested in what you guys think could be the cause!

The printout says the following:

1 fault recognised

01279  027
Longitudinal acceleration sender-G251
Implausible signal
sporadic fault

I understand this points to a sensor in the steering column, what sort of cost/time am I looking at to replace this?

Thanks in advance!