If you want to learn how to work on your car yourself, the Bentley repair manual that came out early this year is wonderful. Pix and everything. Amazon.com has it cheaper than other places.
You might just get a quote from the dealer, and let them diagnose the problem for you and then fix it yourself. Might be the regulators... they go out on aging boxsters.
The airbag deal is easy to avoid. Just remove the negative terminal of the battery for about 15 minutes before you start your work. Have your radio code handy before you do this though.