Volvo Repair: Crankshaft position sensor, crankshaft position sensor, volvo specialist

Question
2000 Volvo S40 1.9  I was driving my car with no issues, parked briefly to run an errand, came back to the car 10 minutes later and the car would not crank, nothing.  after about 15 minutes, the car started right up.  Dropped it off with my mechanic.
Mechanic called to tell me that he suspects the "Crankshaft position sensor" and will need a couple of hours to fully diagnose the issue.

What can you tell me about this type of issue and approximately how long does it typically take to repair such a problem?  Is the part expensive?

Thank you for your time

Answer
The crank position sensor is easy to replace.  Its right on top of the transmission.  It only takes 5 minutes to get it in and out.  Even the sensor is not that expensive as far as sensors go.  I have never replaced one for an INTERMITTENT no start however.  Usually when I see an older model s40 or c70 its always immobilizer issues causing the no start.  You may want to seek a second opinion with a volvo specialist before making any decisions for repairs.

James