Is it worth saving spent primers?

I've been saving my spent primers in hope of selling them to a local recycler. Is it really worth it? Are all primers made out of brass or are some aluminum? Does one have to separate them?

all the ones i have deprimed have been brass , dirty brass but brass , and a 3# coffee can of them is serious weight but it does take time to add up and granted dirty brass isnt as worth as much as copper or even clean brass but it does add up ( one can often trade for lead BTW ) i know guys who take the guilding metal jackets from smelted range bullets in , again it adds up , i made a couple shooting bags from empty lead shot bags , a plastic liner and spent primers ( but i musta washed 40 times first [groan] :P )

I think a lot has to do with where you take them. I have read on forms some will take them, I had some scrap to take in, the scrap yard told me he could only take the primers that were still in the cases, I had a little over a pound of just primers he said he could not take them.
I would check with your local guy, I still save the junk cases, but all my popped primers now go in the trash.