Trouble

I have been having trouble with my car recently. Over the winter I had a new battery installed and last sunday after leaving my car at the airport over a two week trip I returned to find my battery dead. I had it jumped by a professional and then drove it home. The next morning I get in my car and once again it is not starting. I once again have it jumped by a professional and it works fine. It works fine until tonight when I leave work. When I leave work it has a charge and the lights and radio work but it will not start. It sounds like it is about to start but will not completely roll over. I try two times to get the car jumped from seperate indivduals to no avail. Then I call a professional. He says that it is not the battery and is also not the fuel pump because he could here that. He said that he was not sure what the problem is but it might be spark plugs or a coil. I am also new to my area and do not know about this mechanic does this sound right or does anyone have any ideas???

sounds like a failing ignition module.

What is that and how much would it cost to fix?
Any ideas?