Is it a serious problem if the airbag is not working

I test-drove a 97 Altima yesterday. The car is in good shape, 125K miles. Ask for $2500. It has an accident before, the condensor of the airconditioning was changed. One problem is the airbag doesn't work because the light is on all the time. Is it a serious problem? How much does it cost to fix it?

Apart from the danger of not having air bag, check that your state will let you pass the inspection with the airbag light glowing. I would think they wouldn't let that pass. They check seat belt so why not airbag.