i come across a lot of cores...now looking for a good home to sell them to !!!

i service new and used car dealers for scrap. i come across all sorts of cores and sad to say for the last few years have been throwing them out. I've started to collect them and put them aside. I'm now looking for a good home to sell them and maybe someone can educate me that i can even buy them from my customers as well.

maybe its just a distance thing everyone uses as a reason/excuse but why would you ever throw them away am I missing something and misunderstanding what your talking about