BS, no need to pay that retarded ass price unless you have OnStar but obviously you don't. Scosche has a GM09SR that has a chime module, costs about $50 from SonicElectronix. You can even adjust the volume of the chime if need be....there's 3 settings, low, medium and high. It won't damage the head unit but some have had issues with the class II databus system with the factory deck take out, myself included. So what I did was bought a BestKits relocation harness for $45 and relocated the factory deck to my glove box, wired my aftermarket deck to that harness and installed it in the factory location. No more databus problems for me! I have an aftermarket deck and have chime.....well, used to, but since I bought the relocation harness I didn't need the GM09SR anymore.