What price did you pay for GMPP?

[ChevyHDTruckDriver]

I am considering an extended warranty.  What is the best price anyone has paid for a GMPP?  I am looking at the 100,000 mile warranty.  I own a 2001 2500HD 4x4 w/6.0L.  Also, GM has provided me with a component certificate for the engine knock good for 6 years/100,000 miles so full price for a warranty plan is unacceptable since the engine is already covered.