Land Rover Repair: 1997 Discovery LSE V8i, mass air meter, mass air flow sensor

Question
Last February my '97 Discovery would not start and if it did, acted like it wasn't getting enough gas----mechanic revealed code for mass air flow sensor meter and informed me the only thing he could find was in the neighborhood of $1700.  He's an old friend and he helped me with part info. I found the part alot cheaper and in excellent condition on ebay. He replaced it-problem solved.

Two weeks ago problem returned and code says same problem.  Is this a common part to fail or did I just get unlucky. Also I now know that this part has to be exactly the same and I can't seem to find another ANYWHERE. Car is driven by my teenager for school,and money is extremely tight.  Any suggestions for getting it back up and running so I can trade it in on something dependable?

Answer
Mass air meters are commonly available in the $300 range.  I'm not sure what you are talking about at $1700.  In any case, there is no fault that says "bad mass air meter."  The fuel trim faults - if those are what you have - could point to a vacuum leak or injector trouble.  If your mechanic does not understand that it might be time to seek someone with greater diagnostic understanding.