How much to fix a blown head gasket?
 

I have a chance to pick up a 2000 s40 for $750.
The catch is that it has a blown head gasket. It starts and runs though.
Any ideas of how much it would be to get this fixed?
It has 139k miles on it, would it be worth it?

It might cost you about the same for the repair. RepairPrice Estimator - Get an Estimate for a Service or Repair on Your Car : RepairPal
Not a bad deal if you consider everything else the car might need like timing belt set and PCV service.
Ed