It still irks me to no end, when you still see sellers that pack their, (I Mean Buyers) goods so carelessly !

Yes it looks like the damage is to the mounting flange and not the bell of the horn which won't affect the sound..

As for value it will lessen their value a lot.Most buyers will look for horns that are undamaged so you may have a hard time selling at the price you paid.

You should always get insurance when buying items like this..For the small cost it is worth it IMHO.