Call a GM dealer and ask them (give them the symptoms) you may want to give the job to them to do Im worried that the other guys are going for the most costly repair kind of like curing the flue by killing the patient..
Good Luck The Pressure solenoid is much more common than a complete failure!!!

 

sucks about your car man. Sounds similar to what im going through with my 99 suburban. Tranny ran fine then the engine blew. got a new engine then tranny went out 2 weeks later in the middle of the highway. I think engine shops have gathered together to screw us all for more business...

 

Either that, or mechanics don't know jack these days.
Fix one thing break two others.. business?