Problem with my 300 turbo diesel
 

I have an 85 300 turbodiesel and recently i had a trouble with it starting. Never happened before and it was kind of strange. It was almost starting but couldnt engage. I tried few times and the last one I pushed the gas pedal all the way and it did engage, although for the first five seconds it could barely run. After that, it was fine for couple of days, until it did it again and my girlfriend couldnt start it. We took it to a mechanic and he changed the two fuel filters and thought it was all done, but next day it did the same thing:(. Now he charged me 300 to change the prepump and I got a call today that he needs to replace the fuel pump and asked for $1400.00 labor and parts.. I dont know what to do, since I havent done any engine work and I am not familiar with it except for some minor repairs that i did before. Does it make sense that this is the problem that I have with my benz? Please help

So you dont think I really need to change the whole fuel pump? It doesnt seem right to me.. my buddy has 300 k on his and he says its really rare that the fuel pump needs to be replaced.