Maybe I'm just a doubting Thomas type, but my guess is they don't want to do the job. If it needs the shaft too, I believe they will have to pull the transaxle back out.
the sensor is about $150, part #1 here:
http://www.subaruparts.com/diag/?mod...category=835-A
the shaft and seal, etc is around $20, on this page.
http://www.subaruparts.com/diag/?mod...category=156-A
There's also a nylon (or some other plastic type) gear on the shaft I didn't look for.
best of luck.