Airbag light fix or not....?

For about 2 weeks now my airbag light has been on while I am driving, and stays on. I took it to the dealership and they told me the SDM Module needs to be replaced....however I had just picked it up from them two days before because they told me it needed the ignition switch replaced, for a different problem that was occuring (dash lights were staying on when I turned the car off).....they are going to goodwill it and pay for 75% of the repairs.....I was all set to do it and then the day before I was taking it in the original problem with the dash lights happened again....they are going to fix that for free, but should I still pay to get the airbag module fixed? I'm wondering how trust worthy they are and if it's even as bad as they say it is, but if i go somewhere else and that is the problem I will have to pay full price...HELP!