Nissan Repair: nissan 1998 sentra repair

Question
hello my car has been well nmaintaned and owned by me since the beginning. It is a 1998 nissan sentra. 2 weeks ago i brought it in because the car would not start at all even with a boost-- The mechanic said that a lot of pieces in the car were ancient and very very old and probably had not been changed in many years. he replaced the distributor cap and the spark plugs nd the wires and the gas filter. The car ran great or at least started up on a dime since then. But here it is 2 weeks later and the car starts up fast but conks many mny times after I put the car into gear or let my foot off the gas pedal. this has happened even before thisrecent repair but never lasted. By the way- that previous repair that i just mentioned was done was about $295. Everyone stated that for all the stuff he did- the price was decent.
Well as I mentioned I had to bring the car back because it keeps stalling. They did about a 20-25 minute check up - lifted the car up and used flashlights etc- and now state to me that the intake manifold is broken and that it is letting air into the car and diluting the gas and thus it is makiing the car run shaky and bad and making it stall. He said the job is very labor intensive and that the part only costs about $30-- but the labor would be about $500--- my question- is this right-- or am I being taken for a ride???   I did leave the car with him and he is starting to work on it--- I need the car and had no choice?  I just want to feel better that I am not getting ripped off. And if so I will change my mechanic the next time.Thank you

Answer
Hi Monte -

To be honest, it sounds fishy to me. It could be a simple vacuum leak from a hose that is causing your issues, but to be certain I need to look at it which obviously is not possible. Perhaps next time you should get a second opinion.

As this repair, ask the mechanic to tell you what exact part needed to be changed, and ask him to show you the damage, or faulty part.

Let me know what that is, then I can re-assess.

Hope this helps -
aloha
Calvin