1999 NISSAN MAXIMA User Comment / Complaint

I have a 1999 nissan maxima with the check engine light on. took it to the dealer and they told me that all 3 o2 sensors were bad, and they could be replaced for approximately $700. a week later check engine light is back on, and now they are telling me that it is the #3 cylinder misfiring, and they recommend replacing all 6 ignition coils for approximately $1200. i understand that there have been many complaints about the ignition coils, and really do not have the money to pay them again for something that i feel should be replaced by them anyway.