I've got a 2001 Chevy Venture with 134,000 miles. I've been told it has a blown head gasket. What should I expect to pay for repair and is it worth it?

Depending on which side is bad, between 11 and 14.5 hrs labor plus cost of gaskets and coolant. Bad intake manifold gasket is often misdiagnosed as bad head gasket because they can leak coolant into the oil.